1165681 has 4 divisors (see below), whose sum is σ = 1271664. Its totient is φ = 1059700.

The previous prime is 1165667. The next prime is 1165691. The reversal of 1165681 is 1865611.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1165681 - 2¹³ = 1157489 is a prime.

It is a super-2 number, since 2×1165681² = 2717624387522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1165691) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52975 + ... + 52996.

It is an arithmetic number, because the mean of its divisors is an integer number (317916).

2^1165681 is an apocalyptic number.

1165681 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1165681 is a deficient number, since it is larger than the sum of its proper divisors (105983).

1165681 is a wasteful number, since it uses less digits than its factorization.

1165681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105982.

The product of its digits is 1440, while the sum is 28.

The square root of 1165681 is about 1079.6670783163. The cubic root of 1165681 is about 105.2430048217.

Subtracting from 1165681 its product of digits (1440), we obtain a square (1164241 = 1079²).

The spelling of 1165681 in words is "one million, one hundred sixty-five thousand, six hundred eighty-one".