861732864 has 136 divisors (see below), whose sum is σ = 2558505920. Its totient is φ = 286654464.

The previous prime is 861732847. The next prime is 861732871. The reversal of 861732864 is 468237168.

861732864 is a `hidden beast` number, since 8 + 617 + 3 + 28 + 6 + 4 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1769229 + ... + 1769715.

Almost surely, 2^861732864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 861732864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1279252960).

861732864 is an abundant number, since it is smaller than the sum of its proper divisors (1696773056).

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

861732864 is an frugal number, since it uses more digits than its factorization.

861732864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 528 (or 492 counting only the distinct ones).

The product of its digits is 387072, while the sum is 45.

The square root of 861732864 is about 29355.2868151548. The cubic root of 861732864 is about 951.6068333879.

The spelling of 861732864 in words is "eight hundred sixty-one million, seven hundred thirty-two thousand, eight hundred sixty-four".