8172561664 has 36 divisors (see below), whose sum is σ = 17022481056. Its totient is φ = 3908613632.

The previous prime is 8172561629. The next prime is 8172561679. The reversal of 8172561664 is 4661652718.

It is a Harshad number since it is a multiple of its sum of digits (46).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 688114 + ... + 699889.

It is an arithmetic number, because the mean of its divisors is an integer number (472846696).

Almost surely, 2^8172561664 is an apocalyptic number.

It is an amenable number.

8172561664 is an abundant number, since it is smaller than the sum of its proper divisors (8849919392).

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

8172561664 is a wasteful number, since it uses less digits than its factorization.

8172561664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1388042 (or 1388028 counting only the distinct ones).

The product of its digits is 483840, while the sum is 46.

The square root of 8172561664 is about 90402.2215656230. The cubic root of 8172561664 is about 2014.2779659516.

The spelling of 8172561664 in words is "eight billion, one hundred seventy-two million, five hundred sixty-one thousand, six hundred sixty-four".