215172864 has 108 divisors (see below), whose sum is σ = 630978712. Its totient is φ = 70502400.

The previous prime is 215172863. The next prime is 215172899. The reversal of 215172864 is 468271512.

It is a super-2 number, since 2×215172864² = 92598722803924992, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215172863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 139779 + ... + 141309.

Almost surely, 2^215172864 is an apocalyptic number.

215172864 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 215172864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (315489356).

215172864 is an abundant number, since it is smaller than the sum of its proper divisors (415805848).

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

215172864 is a wasteful number, since it uses less digits than its factorization.

215172864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1614 (or 1597 counting only the distinct ones).

The product of its digits is 26880, while the sum is 36.

The square root of 215172864 is about 14668.7717277214. The cubic root of 215172864 is about 599.2331536620.

The spelling of 215172864 in words is "two hundred fifteen million, one hundred seventy-two thousand, eight hundred sixty-four".