51640742772 has 72 divisors (see below), whose sum is σ = 139393712640. Its totient is φ = 16083869760.

The previous prime is 51640742749. The next prime is 51640742819. The reversal of 51640742772 is 27724704615.

51640742772 is a `hidden beast` number, since 516 + 40 + 7 + 4 + 27 + 72 = 666.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 765448 + ... + 830175.

Almost surely, 2^51640742772 is an apocalyptic number.

It is an amenable number.

51640742772 is an abundant number, since it is smaller than the sum of its proper divisors (87752969868).

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

51640742772 is a wasteful number, since it uses less digits than its factorization.

51640742772 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1595693 (or 1595688 counting only the distinct ones).

The product of its (nonzero) digits is 658560, while the sum is 45.

The spelling of 51640742772 in words is "fifty-one billion, six hundred forty million, seven hundred forty-two thousand, seven hundred seventy-two".