251261561374 has 16 divisors (see below), whose sum is σ = 378891319248. Its totient is φ = 124966153792.

The previous prime is 251261561339. The next prime is 251261561393. The reversal of 251261561374 is 473165162152.

It is a self number, because there is not a number n which added to its sum of digits gives 251261561374.

It is a congruent number.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 128239 + ... + 720394.

It is an arithmetic number, because the mean of its divisors is an integer number (23680707453).

Almost surely, 2^251261561374 is an apocalyptic number.

251261561374 is a deficient number, since it is larger than the sum of its proper divisors (127629757874).

251261561374 is a wasteful number, since it uses less digits than its factorization.

251261561374 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 849419.

The product of its digits is 302400, while the sum is 43.

The spelling of 251261561374 in words is "two hundred fifty-one billion, two hundred sixty-one million, five hundred sixty-one thousand, three hundred seventy-four".