215560656 has 80 divisors (see below), whose sum is σ = 623769600. Its totient is φ = 71269632.

The previous prime is 215560637. The next prime is 215560691. The reversal of 215560656 is 656065512.

It is a happy number.

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

It is a self number, because there is not a number n which added to its sum of digits gives 215560656.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 52900 + ... + 56828.

It is an arithmetic number, because the mean of its divisors is an integer number (7797120).

Almost surely, 2^215560656 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 215560656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (311884800).

215560656 is an abundant number, since it is smaller than the sum of its proper divisors (408208944).

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

215560656 is a wasteful number, since it uses less digits than its factorization.

215560656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4073 (or 4061 counting only the distinct ones).

The product of its (nonzero) digits is 54000, while the sum is 36.

The square root of 215560656 is about 14681.9840621082. The cubic root of 215560656 is about 599.5929238775.

The spelling of 215560656 in words is "two hundred fifteen million, five hundred sixty thousand, six hundred fifty-six".