215265891 has 16 divisors (see below), whose sum is σ = 296801280. Its totient is φ = 138636960.

The previous prime is 215265863. The next prime is 215265893. The reversal of 215265891 is 198562512.

215265891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 215265891 - 2²³ = 206877283 is a prime.

It is not an unprimeable number, because it can be changed into a prime (215265893) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 61825 + ... + 65213.

It is an arithmetic number, because the mean of its divisors is an integer number (18550080).

Almost surely, 2^215265891 is an apocalyptic number.

215265891 is a deficient number, since it is larger than the sum of its proper divisors (81535389).

215265891 is a wasteful number, since it uses less digits than its factorization.

215265891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4106.

The product of its digits is 43200, while the sum is 39.

The square root of 215265891 is about 14671.9423049574. The cubic root of 215265891 is about 599.3194979311.

The spelling of 215265891 in words is "two hundred fifteen million, two hundred sixty-five thousand, eight hundred ninety-one".