215656 has 16 divisors (see below), whose sum is σ = 462240. Its totient is φ = 92400.

The previous prime is 215653. The next prime is 215659. The reversal of 215656 is 656512.

It is an interprime number because it is at equal distance from previous prime (215653) and next prime (215659).

It is a self number, because there is not a number n which added to its sum of digits gives 215656.

It is not an unprimeable number, because it can be changed into a prime (215653) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1870 + ... + 1981.

It is an arithmetic number, because the mean of its divisors is an integer number (28890).

2²¹⁵⁶⁵⁶ is an apocalyptic number.

It is an amenable number.

215656 is an abundant number, since it is smaller than the sum of its proper divisors (246584).

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

215656 is a wasteful number, since it uses less digits than its factorization.

215656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3864 (or 3860 counting only the distinct ones).

The product of its digits is 1800, while the sum is 25.

The square root of 215656 is about 464.3877690034. The cubic root of 215656 is about 59.9681312242.

The spelling of 215656 in words is "two hundred fifteen thousand, six hundred fifty-six".