215256645 has 24 divisors (see below), whose sum is σ = 373946976. Its totient is φ = 114546528.

The previous prime is 215256637. The next prime is 215256649. The reversal of 215256645 is 546652512.

215256645 is a `hidden beast` number, since 2 + 1 + 5 + 2 + 5 + 6 + 645 = 666.

It is not a de Polignac number, because 215256645 - 2³ = 215256637 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (215256649) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 15894 + ... + 26136.

It is an arithmetic number, because the mean of its divisors is an integer number (15581124).

Almost surely, 2^215256645 is an apocalyptic number.

It is an amenable number.

215256645 is a deficient number, since it is larger than the sum of its proper divisors (158690331).

215256645 is a wasteful number, since it uses less digits than its factorization.

215256645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10721 (or 10718 counting only the distinct ones).

The product of its digits is 72000, while the sum is 36.

The square root of 215256645 is about 14671.6272103676. The cubic root of 215256645 is about 599.3109172446.

The spelling of 215256645 in words is "two hundred fifteen million, two hundred fifty-six thousand, six hundred forty-five".