1040 has 20 divisors (see below), whose sum is σ = 2604. Its totient is φ = 384.

The previous prime is 1039. The next prime is 1049. The reversal of 1040 is 401.

It can be written as a sum of positive squares in 2 ways, for example, as 256 + 784 = 16^2 + 28^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a Harshad number since it is a multiple of its sum of digits (5).

It is a super Niven number, because it is divisible the sum of any subset of its (nonzero) digits.

1040 is an undulating number in base 8.

It is a nialpdrome in base 11, base 13, base 14 and base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (2) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74 + ... + 86.

2¹⁰⁴⁰ is an apocalyptic number.

1040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1302).

1040 is an abundant number, since it is smaller than the sum of its proper divisors (1564).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1040 is a wasteful number, since it uses less digits than its factorization.

1040 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26 (or 20 counting only the distinct ones).

The product of its (nonzero) digits is 4, while the sum is 5.

The square root of 1040 is about 32.2490309932. The cubic root of 1040 is about 10.1315940382.

Adding to 1040 its reverse (401), we get a palindrome (1441).

It can be divided in two parts, 10 and 40, that multiplied together give a square (400 = 20²).

The spelling of 1040 in words is "one thousand, forty", and thus it is an iban number.