215867865 has 16 divisors (see below), whose sum is σ = 345767616. Its totient is φ = 115003200.

The previous prime is 215867833. The next prime is 215867867. The reversal of 215867865 is 568768512.

It is not a de Polignac number, because 215867865 - 2⁵ = 215867833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (215867867) by changing a digit.

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, 7155 + ... + 21975.

It is an arithmetic number, because the mean of its divisors is an integer number (21610476).

Almost surely, 2^215867865 is an apocalyptic number.

It is an amenable number.

215867865 is a deficient number, since it is larger than the sum of its proper divisors (129899751).

215867865 is a wasteful number, since it uses less digits than its factorization.

215867865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15800.

The product of its digits is 806400, while the sum is 48.

The square root of 215867865 is about 14692.4424450123. The cubic root of 215867865 is about 599.8776278212.

The spelling of 215867865 in words is "two hundred fifteen million, eight hundred sixty-seven thousand, eight hundred sixty-five".