51661193922 has 90 divisors (see below), whose sum is σ = 121643706093. Its totient is φ = 15845607648.

The previous prime is 51661193893. The next prime is 51661193939. The reversal of 51661193922 is 22939116615.

51661193922 is a `hidden beast` number, since 5 + 1 + 6 + 611 + 9 + 3 + 9 + 22 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 48669213321 + 2991980601 = 220611^2 + 54699^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=160719.

It is an unprimeable number.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 162968908 + ... + 162969224.

Almost surely, 2^51661193922 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51661193922

51661193922 is an abundant number, since it is smaller than the sum of its proper divisors (69982512171).

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

51661193922 is an frugal number, since it uses more digits than its factorization.

51661193922 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 694 (or 335 counting only the distinct ones).

The product of its digits is 174960, while the sum is 45.

The spelling of 51661193922 in words is "fifty-one billion, six hundred sixty-one million, one hundred ninety-three thousand, nine hundred twenty-two".