251756540442 has 48 divisors (see below), whose sum is σ = 595126295712. Its totient is φ = 76281478560.

The previous prime is 251756540423. The next prime is 251756540467. The reversal of 251756540442 is 244045657152.

251756540442 is a `hidden beast` number, since 2 + 5 + 1 + 7 + 565 + 40 + 4 + 42 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1872868 + ... + 2002784.

It is an arithmetic number, because the mean of its divisors is an integer number (12398464494).

Almost surely, 2^251756540442 is an apocalyptic number.

251756540442 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

251756540442 is an abundant number, since it is smaller than the sum of its proper divisors (343369755270).

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

251756540442 is a wasteful number, since it uses less digits than its factorization.

251756540442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 139723 (or 139720 counting only the distinct ones).

The product of its (nonzero) digits is 1344000, while the sum is 45.

The spelling of 251756540442 in words is "two hundred fifty-one billion, seven hundred fifty-six million, five hundred forty thousand, four hundred forty-two".