215664768 has 320 divisors, whose sum is σ = 734595840. Its totient is φ = 62208000.

The previous prime is 215664751. The next prime is 215664773. The reversal of 215664768 is 867466512.

215664768 is a `hidden beast` number, since 21 + 566 + 4 + 7 + 68 = 666.

It is a super-2 number, since 2×215664768² = 93022584312987648, which contains 22 as substring.

Its product of digits (483840) is a multiple of the sum of its prime divisors (108).

It is an unprimeable number.

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 39 ways as a sum of consecutive naturals, for example, 3535458 + ... + 3535518.

It is an arithmetic number, because the mean of its divisors is an integer number (2295612).

Almost surely, 2^215664768 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 215664768, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (367297920).

215664768 is an abundant number, since it is smaller than the sum of its proper divisors (518931072).

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

215664768 is a wasteful number, since it uses less digits than its factorization.

215664768 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 129 (or 108 counting only the distinct ones).

The product of its digits is 483840, while the sum is 45.

The square root of 215664768 is about 14685.5292039477. The cubic root of 215664768 is about 599.6894392811.

The spelling of 215664768 in words is "two hundred fifteen million, six hundred sixty-four thousand, seven hundred sixty-eight".