251630128156 has 18 divisors (see below), whose sum is σ = 484024069760. Its totient is φ = 114377330760.

The previous prime is 251630128147. The next prime is 251630128157. The reversal of 251630128156 is 651821036152.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251630128157) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 259947996 + ... + 259948963.

Almost surely, 2^251630128156 is an apocalyptic number.

It is an amenable number.

251630128156 is a deficient number, since it is larger than the sum of its proper divisors (232393941604).

251630128156 is a wasteful number, since it uses less digits than its factorization.

251630128156 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 519896985 (or 519896972 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 40.

The spelling of 251630128156 in words is "two hundred fifty-one billion, six hundred thirty million, one hundred twenty-eight thousand, one hundred fifty-six".