51620932990638 has 48 divisors (see below), whose sum is σ = 122013605615616. Its totient is φ = 15642643983120.

The previous prime is 51620932990637. The next prime is 51620932990699. The reversal of 51620932990638 is 83609923902615.

51620932990638 is a `hidden beast` number, since 5 + 16 + 209 + 329 + 90 + 6 + 3 + 8 = 666.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51620932990637) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 79535545 + ... + 80181947.

It is an arithmetic number, because the mean of its divisors is an integer number (2541950116992).

Almost surely, 2^{51620932990638} is an apocalyptic number.

51620932990638 is an abundant number, since it is smaller than the sum of its proper divisors (70392672624978).

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

51620932990638 is a wasteful number, since it uses less digits than its factorization.

51620932990638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1049749 (or 1049746 counting only the distinct ones).

The product of its (nonzero) digits is 37791360, while the sum is 63.

The spelling of 51620932990638 in words is "fifty-one trillion, six hundred twenty billion, nine hundred thirty-two million, nine hundred ninety thousand, six hundred thirty-eight".