221902865 has 16 divisors (see below), whose sum is σ = 274893696. Its totient is φ = 171849600.

The previous prime is 221902859. The next prime is 221902871. The reversal of 221902865 is 568209122.

It is a happy number.

221902865 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (221902859) and next prime (221902871).

It is not a de Polignac number, because 221902865 - 2¹⁸ = 221640721 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 22724 + ... + 30986.

It is an arithmetic number, because the mean of its divisors is an integer number (17180856).

Almost surely, 2^221902865 is an apocalyptic number.

It is an amenable number.

221902865 is a deficient number, since it is larger than the sum of its proper divisors (52990831).

221902865 is a wasteful number, since it uses less digits than its factorization.

221902865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8440.

The product of its (nonzero) digits is 17280, while the sum is 35.

The square root of 221902865 is about 14896.4044319426. The cubic root of 221902865 is about 605.4165698790.

The spelling of 221902865 in words is "two hundred twenty-one million, nine hundred two thousand, eight hundred sixty-five".