20075640 has 128 divisors (see below), whose sum is σ = 68765760. Its totient is φ = 4644864.

The previous prime is 20075621. The next prime is 20075659. The reversal of 20075640 is 4657002.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (20075621) and next prime (20075659).

It is a super-3 number, since 3×20075640³ (a number of 23 digits) contains 333 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a self number, because there is not a number n which added to its sum of digits gives 20075640.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26142 + ... + 26898.

Almost surely, 2^20075640 is an apocalyptic number.

20075640 is a gapful number since it is divisible by the number (20) 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 20075640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34382880).

20075640 is an abundant number, since it is smaller than the sum of its proper divisors (48690120).

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

20075640 is a wasteful number, since it uses less digits than its factorization.

20075640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 801 (or 797 counting only the distinct ones).

The product of its (nonzero) digits is 1680, while the sum is 24.

The square root of 20075640 is about 4480.5847832621. The cubic root of 20075640 is about 271.7835287474.

Subtracting from 20075640 its sum of digits (24), we obtain a triangular number (20075616 = T₆₃₃₆).

The spelling of 20075640 in words is "twenty million, seventy-five thousand, six hundred forty".