215986 has 8 divisors (see below), whose sum is σ = 328320. Its totient is φ = 106548.

The previous prime is 215983. The next prime is 216023. The reversal of 215986 is 689512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (215981) 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, 526 + ... + 841.

It is an arithmetic number, because the mean of its divisors is an integer number (41040).

2²¹⁵⁹⁸⁶ is an apocalyptic number.

215986 is a deficient number, since it is larger than the sum of its proper divisors (112334).

215986 is a wasteful number, since it uses less digits than its factorization.

215986 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1448.

The product of its digits is 4320, while the sum is 31.

The square root of 215986 is about 464.7429396989. The cubic root of 215986 is about 59.9987036757.

The spelling of 215986 in words is "two hundred fifteen thousand, nine hundred eighty-six".