215988 has 24 divisors (see below), whose sum is σ = 517440. Its totient is φ = 70080.

The previous prime is 215983. The next prime is 216023. The reversal of 215988 is 889512.

It is a happy number.

It is a super-2 number, since 2×215988² = 93301632288, which contains 22 as substring.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 215988.

It is not an unprimeable number, because it can be changed into a prime (215981) by changing a digit.

215988 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 273 + ... + 711.

It is an arithmetic number, because the mean of its divisors is an integer number (21560).

2²¹⁵⁹⁸⁸ is an apocalyptic number.

It is an amenable number.

215988 is an abundant number, since it is smaller than the sum of its proper divisors (301452).

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

215988 is a wasteful number, since it uses less digits than its factorization.

215988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 487 (or 485 counting only the distinct ones).

The product of its digits is 5760, while the sum is 33.

The square root of 215988 is about 464.7450914211. The cubic root of 215988 is about 59.9988888683.

The spelling of 215988 in words is "two hundred fifteen thousand, nine hundred eighty-eight".