157215865 has 4 divisors (see below), whose sum is σ = 188659044. Its totient is φ = 125772688.

The previous prime is 157215859. The next prime is 157215871. The reversal of 157215865 is 568512751.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (157215859) and next prime (157215871).

It can be written as a sum of positive squares in 2 ways, for example, as 22005481 + 135210384 = 4691^2 + 11628^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-157215865 is a prime.

It is a Duffinian number.

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 3 ways as a sum of consecutive naturals, for example, 15721582 + ... + 15721591.

It is an arithmetic number, because the mean of its divisors is an integer number (47164761).

Almost surely, 2^157215865 is an apocalyptic number.

It is an amenable number.

157215865 is a deficient number, since it is larger than the sum of its proper divisors (31443179).

157215865 is an equidigital number, since it uses as much as digits as its factorization.

157215865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31443178.

The product of its digits is 84000, while the sum is 40.

The square root of 157215865 is about 12538.5750785326. The cubic root of 157215865 is about 539.7162031859.

The spelling of 157215865 in words is "one hundred fifty-seven million, two hundred fifteen thousand, eight hundred sixty-five".