217864469664 has 96 divisors (see below), whose sum is σ = 636854400000. Its totient is φ = 72459620352.

The previous prime is 217864469653. The next prime is 217864469677. The reversal of 217864469664 is 466964468712.

It is a happy number.

217864469664 is a `hidden beast` number, since 21 + 7 + 86 + 446 + 96 + 6 + 4 = 666.

It is a tau number, because it is divible by the number of its divisors (96).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 107137 + ... + 668735.

It is an arithmetic number, because the mean of its divisors is an integer number (6633900000).

Almost surely, 2^217864469664 is an apocalyptic number.

217864469664 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 217864469664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (318427200000).

217864469664 is an abundant number, since it is smaller than the sum of its proper divisors (418989930336).

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

217864469664 is a wasteful number, since it uses less digits than its factorization.

217864469664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 562067 (or 562053 counting only the distinct ones).

The product of its digits is 83607552, while the sum is 63.

The spelling of 217864469664 in words is "two hundred seventeen billion, eight hundred sixty-four million, four hundred sixty-nine thousand, six hundred sixty-four".