216571264 has 64 divisors (see below), whose sum is σ = 531044640. Its totient is φ = 85671936.

The previous prime is 216571259. The next prime is 216571339. The reversal of 216571264 is 462175612.

It is a tau number, because it is divible by the number of its divisors (64).

It is a super-2 number, since 2×216571264² = 93806224781115392, which contains 22 as substring.

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, 2352 + ... + 20944.

Almost surely, 2^216571264 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 216571264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (265522320).

216571264 is an abundant number, since it is smaller than the sum of its proper divisors (314473376).

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

216571264 is a wasteful number, since it uses less digits than its factorization.

216571264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18627 (or 18615 counting only the distinct ones).

The product of its digits is 20160, while the sum is 34.

The square root of 216571264 is about 14716.3604196146. The cubic root of 216571264 is about 600.5284825219.

The spelling of 216571264 in words is "two hundred sixteen million, five hundred seventy-one thousand, two hundred sixty-four".