215538660 has 216 divisors, whose sum is σ = 718937856. Its totient is φ = 52202880.

The previous prime is 215538647. The next prime is 215538707. The reversal of 215538660 is 66835512.

215538660 is a `hidden beast` number, since 21 + 553 + 86 + 6 + 0 = 666.

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

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 2014327 + ... + 2014433.

It is an arithmetic number, because the mean of its divisors is an integer number (3328416).

Almost surely, 2^215538660 is an apocalyptic number.

215538660 is a gapful number since it is divisible by the number (20) 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 215538660, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (359468928).

215538660 is an abundant number, since it is smaller than the sum of its proper divisors (503399196).

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

215538660 is a wasteful number, since it uses less digits than its factorization.

215538660 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 191 (or 167 counting only the distinct ones).

The product of its (nonzero) digits is 43200, while the sum is 36.

The square root of 215538660 is about 14681.2349616781. The cubic root of 215538660 is about 599.5725288530.

The spelling of 215538660 in words is "two hundred fifteen million, five hundred thirty-eight thousand, six hundred sixty".