71507664657 has 24 divisors (see below), whose sum is σ = 121346342208. Its totient is φ = 40004287200.

The previous prime is 71507664637. The next prime is 71507664673. The reversal of 71507664657 is 75646670517.

71507664657 is a `hidden beast` number, since 71 + 50 + 7 + 66 + 465 + 7 = 666.

It is not a de Polignac number, because 71507664657 - 2¹² = 71507660561 is a prime.

It is a super-2 number, since 2×71507664657² (a number of 23 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (71507664637) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 27779469 + ... + 27782042.

It is an arithmetic number, because the mean of its divisors is an integer number (5056097592).

Almost surely, 2^71507664657 is an apocalyptic number.

It is an amenable number.

71507664657 is a deficient number, since it is larger than the sum of its proper divisors (49838677551).

71507664657 is a wasteful number, since it uses less digits than its factorization.

71507664657 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 55561541 (or 55561538 counting only the distinct ones).

The product of its (nonzero) digits is 7408800, while the sum is 54.

It can be divided in two parts, 71507 and 664657, that added together give a square (736164 = 858²).

The spelling of 71507664657 in words is "seventy-one billion, five hundred seven million, six hundred sixty-four thousand, six hundred fifty-seven".