215868 has 12 divisors (see below), whose sum is σ = 503720. Its totient is φ = 71952.

The previous prime is 215863. The next prime is 215893. The reversal of 215868 is 868512.

It is a tau number, because it is divible by the number of its divisors (12).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215863) by changing a digit.

215868 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 3 ways as a sum of consecutive naturals, for example, 8983 + ... + 9006.

2²¹⁵⁸⁶⁸ is an apocalyptic number.

It is an amenable number.

215868 is an abundant number, since it is smaller than the sum of its proper divisors (287852).

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

215868 is a wasteful number, since it uses less digits than its factorization.

215868 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17996 (or 17994 counting only the distinct ones).

The product of its digits is 3840, while the sum is 30.

The square root of 215868 is about 464.6159704530. The cubic root of 215868 is about 59.9877752872.

The spelling of 215868 in words is "two hundred fifteen thousand, eight hundred sixty-eight".