215135856 has 120 divisors (see below), whose sum is σ = 664447056. Its totient is φ = 64558080.

The previous prime is 215135849. The next prime is 215135863. The reversal of 215135856 is 658531512.

It is a happy number.

215135856 is a `hidden beast` number, since 21 + 51 + 3 + 585 + 6 = 666.

215135856 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (215135849) and next prime (215135863).

It is a Smith number, since the sum of its digits (36) coincides with the sum of the digits of its prime factors.

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 215135856.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 75351 + ... + 78153.

Almost surely, 2^215135856 is an apocalyptic number.

215135856 is a gapful number since it is divisible by the number (26) 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 215135856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (332223528).

215135856 is an abundant number, since it is smaller than the sum of its proper divisors (449311200).

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

215135856 is a wasteful number, since it uses less digits than its factorization.

215135856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2871 (or 2862 counting only the distinct ones).

The product of its digits is 36000, while the sum is 36.

The square root of 215135856 is about 14667.5102181659. The cubic root of 215135856 is about 599.1987972665.

The spelling of 215135856 in words is "two hundred fifteen million, one hundred thirty-five thousand, eight hundred fifty-six".