216864856656 has 160 divisors (see below), whose sum is σ = 748851276800. Its totient is φ = 58700246400.

The previous prime is 216864856577. The next prime is 216864856711. The reversal of 216864856656 is 656658468612.

It is a happy number.

216864856656 is a `hidden beast` number, since 2 + 1 + 6 + 8 + 64 + 8 + 566 + 5 + 6 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a junction number, because it is equal to n+sod(n) for n = 216864856593 and 216864856602.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1829770 + ... + 1944681.

It is an arithmetic number, because the mean of its divisors is an integer number (4680320480).

Almost surely, 2^216864856656 is an apocalyptic number.

It is an amenable number.

216864856656 is an abundant number, since it is smaller than the sum of its proper divisors (531986420144).

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

216864856656 is a wasteful number, since it uses less digits than its factorization.

216864856656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3774494 (or 3774482 counting only the distinct ones).

The product of its digits is 99532800, while the sum is 63.

The spelling of 216864856656 in words is "two hundred sixteen billion, eight hundred sixty-four million, eight hundred fifty-six thousand, six hundred fifty-six".