251368157 has 4 divisors (see below), whose sum is σ = 264598080. Its totient is φ = 238138236.

The previous prime is 251368133. The next prime is 251368177. The reversal of 251368157 is 751863152.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 251368157 - 2²⁰ = 250319581 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 251368157.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251368177) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6614933 + ... + 6614970.

It is an arithmetic number, because the mean of its divisors is an integer number (66149520).

Almost surely, 2^251368157 is an apocalyptic number.

It is an amenable number.

251368157 is a deficient number, since it is larger than the sum of its proper divisors (13229923).

251368157 is a wasteful number, since it uses less digits than its factorization.

251368157 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13229922.

The product of its digits is 50400, while the sum is 38.

The square root of 251368157 is about 15854.5941922208. The cubic root of 251368157 is about 631.1076148225.

The spelling of 251368157 in words is "two hundred fifty-one million, three hundred sixty-eight thousand, one hundred fifty-seven".