51131990994 has 32 divisors (see below), whose sum is σ = 119359789056. Its totient is φ = 14298306960.

The previous prime is 51131990963. The next prime is 51131991013. The reversal of 51131990994 is 49909913115.

It is a super-2 number, since 2×51131990994² (a number of 22 digits) contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12949392 + ... + 12953339.

It is an arithmetic number, because the mean of its divisors is an integer number (3729993408).

Almost surely, 2^51131990994 is an apocalyptic number.

51131990994 is an abundant number, since it is smaller than the sum of its proper divisors (68227798062).

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

51131990994 is a wasteful number, since it uses less digits than its factorization.

51131990994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25902790.

The product of its (nonzero) digits is 393660, while the sum is 51.

The spelling of 51131990994 in words is "fifty-one billion, one hundred thirty-one million, nine hundred ninety thousand, nine hundred ninety-four".