251401157566 has 12 divisors (see below), whose sum is σ = 408340933992. Its totient is φ = 116031303336.

The previous prime is 251401157543. The next prime is 251401157569. The reversal of 251401157566 is 665751104152.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (251401157569) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 371894866 + ... + 371895541.

It is an arithmetic number, because the mean of its divisors is an integer number (34028411166).

Almost surely, 2^251401157566 is an apocalyptic number.

251401157566 is a gapful number since it is divisible by the number (26) formed by its first and last digit.

251401157566 is a deficient number, since it is larger than the sum of its proper divisors (156939776426).

251401157566 is a wasteful number, since it uses less digits than its factorization.

251401157566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 743790435 (or 743790422 counting only the distinct ones).

The product of its (nonzero) digits is 252000, while the sum is 43.

The spelling of 251401157566 in words is "two hundred fifty-one billion, four hundred one million, one hundred fifty-seven thousand, five hundred sixty-six".