251791195479164 has 24 divisors (see below), whose sum is σ = 508968298884528. Its totient is φ = 107718158493440.

The previous prime is 251791195479163. The next prime is 251791195479179. The reversal of 251791195479164 is 461974591197152.

It is a super-2 number, since 2×251791195479164² (a number of 30 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251791195479163) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 168309621899 + ... + 168309623394.

It is an arithmetic number, because the mean of its divisors is an integer number (21207012453522).

Almost surely, 2^{251791195479164} is an apocalyptic number.

It is an amenable number.

251791195479164 is an abundant number, since it is smaller than the sum of its proper divisors (257177103405364).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

251791195479164 is a wasteful number, since it uses less digits than its factorization.

251791195479164 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 336619245325 (or 336619245323 counting only the distinct ones).

The product of its digits is 171460800, while the sum is 71.

The spelling of 251791195479164 in words is "two hundred fifty-one trillion, seven hundred ninety-one billion, one hundred ninety-five million, four hundred seventy-nine thousand, one hundred sixty-four".