251138238351 has 144 divisors (see below), whose sum is σ = 460673015040. Its totient is φ = 119054707200.

The previous prime is 251138238313. The next prime is 251138238371. The reversal of 251138238351 is 153832831152.

It is not a de Polignac number, because 251138238351 - 2⁷ = 251138238223 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251138238301) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 38215896 + ... + 38222466.

It is an arithmetic number, because the mean of its divisors is an integer number (3199118160).

Almost surely, 2^251138238351 is an apocalyptic number.

251138238351 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

251138238351 is a deficient number, since it is larger than the sum of its proper divisors (209534776689).

251138238351 is a wasteful number, since it uses less digits than its factorization.

251138238351 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6718 (or 6694 counting only the distinct ones).

The product of its digits is 172800, while the sum is 42.

The spelling of 251138238351 in words is "two hundred fifty-one billion, one hundred thirty-eight million, two hundred thirty-eight thousand, three hundred fifty-one".