51513655122621 has 24 divisors (see below), whose sum is σ = 78794640759744. Its totient is φ = 32318580355200.

The previous prime is 51513655122551. The next prime is 51513655122707. The reversal of 51513655122621 is 12622155631515.

51513655122621 is a `hidden beast` number, since 5 + 1 + 5 + 1 + 3 + 6 + 5 + 5 + 12 + 2 + 621 = 666.

It is not a de Polignac number, because 51513655122621 - 2²⁶ = 51513588013757 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51513655122421) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18002305 + ... + 20666646.

It is an arithmetic number, because the mean of its divisors is an integer number (3283110031656).

Almost surely, 2^{51513655122621} is an apocalyptic number.

51513655122621 is a gapful number since it is divisible by the number (51) formed by its first and last digit.

It is an amenable number.

51513655122621 is a deficient number, since it is larger than the sum of its proper divisors (27280985637123).

51513655122621 is a wasteful number, since it uses less digits than its factorization.

51513655122621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 38677681 (or 38677678 counting only the distinct ones).

The product of its digits is 540000, while the sum is 45.

The spelling of 51513655122621 in words is "fifty-one trillion, five hundred thirteen billion, six hundred fifty-five million, one hundred twenty-two thousand, six hundred twenty-one".