51661720676 has 24 divisors (see below), whose sum is σ = 93543179520. Its totient is φ = 24935434272.

The previous prime is 51661720673. The next prime is 51661720711. The reversal of 51661720676 is 67602716615.

It is a self number, because there is not a number n which added to its sum of digits gives 51661720676.

It is not an unprimeable number, because it can be changed into a prime (51661720673) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 620045 + ... + 698411.

It is an arithmetic number, because the mean of its divisors is an integer number (3897632480).

Almost surely, 2^51661720676 is an apocalyptic number.

It is an amenable number.

51661720676 is a deficient number, since it is larger than the sum of its proper divisors (41881458844).

51661720676 is a wasteful number, since it uses less digits than its factorization.

51661720676 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84083 (or 84081 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 47.

The spelling of 51661720676 in words is "fifty-one billion, six hundred sixty-one million, seven hundred twenty thousand, six hundred seventy-six".