216957761664 has 256 divisors, whose sum is σ = 665542656000. Its totient is φ = 61339299840.

The previous prime is 216957761633. The next prime is 216957761707. The reversal of 216957761664 is 466167759612.

It is a junction number, because it is equal to n+sod(n) for n = 216957761598 and 216957761607.

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, 204483694 + ... + 204484754.

It is an arithmetic number, because the mean of its divisors is an integer number (2599776000).

Almost surely, 2^216957761664 is an apocalyptic number.

216957761664 is a gapful number since it is divisible by the number (24) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 216957761664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (332771328000).

216957761664 is an abundant number, since it is smaller than the sum of its proper divisors (448584894336).

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

216957761664 is a wasteful number, since it uses less digits than its factorization.

216957761664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1811 (or 1799 counting only the distinct ones).

The product of its digits is 22861440, while the sum is 60.

The spelling of 216957761664 in words is "two hundred sixteen billion, nine hundred fifty-seven million, seven hundred sixty-one thousand, six hundred sixty-four".