215940865 has 16 divisors (see below), whose sum is σ = 296593920. Its totient is φ = 147850560.

The previous prime is 215940847. The next prime is 215940877. The reversal of 215940865 is 568049512.

It is not a de Polignac number, because 215940865 - 2⁷ = 215940737 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20875 + ... + 29455.

It is an arithmetic number, because the mean of its divisors is an integer number (18537120).

Almost surely, 2^215940865 is an apocalyptic number.

It is an amenable number.

215940865 is a deficient number, since it is larger than the sum of its proper divisors (80653055).

215940865 is an equidigital number, since it uses as much as digits as its factorization.

215940865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9312.

The product of its (nonzero) digits is 86400, while the sum is 40.

The square root of 215940865 is about 14694.9265054304. The cubic root of 215940865 is about 599.9452403728.

The spelling of 215940865 in words is "two hundred fifteen million, nine hundred forty thousand, eight hundred sixty-five".