81265707 has 32 divisors (see below), whose sum is σ = 123379200. Its totient is φ = 52851744.

The previous prime is 81265699. The next prime is 81265721. The reversal of 81265707 is 70756218.

81265707 is a `hidden beast` number, since 81 + 2 + 6 + 570 + 7 = 666.

It is not a de Polignac number, because 81265707 - 2³ = 81265699 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81265777) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 301969 + ... + 302237.

It is an arithmetic number, because the mean of its divisors is an integer number (3855600).

Almost surely, 2^81265707 is an apocalyptic number.

81265707 is a deficient number, since it is larger than the sum of its proper divisors (42113493).

81265707 is a wasteful number, since it uses less digits than its factorization.

81265707 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 512 (or 506 counting only the distinct ones).

The product of its (nonzero) digits is 23520, while the sum is 36.

The square root of 81265707 is about 9014.7494141546. The cubic root of 81265707 is about 433.1474606519.

The spelling of 81265707 in words is "eighty-one million, two hundred sixty-five thousand, seven hundred seven".