51125638464 has 336 divisors, whose sum is σ = 156112220160. Its totient is φ = 15972802560.

The previous prime is 51125638429. The next prime is 51125638469. The reversal of 51125638464 is 46483652115.

51125638464 is a `hidden beast` number, since 5 + 1 + 1 + 2 + 5 + 638 + 4 + 6 + 4 = 666.

51125638464 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×51125638464² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51125638469) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 84226449 + ... + 84227055.

Almost surely, 2^51125638464 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51125638464, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (78056110080).

51125638464 is an abundant number, since it is smaller than the sum of its proper divisors (104986581696).

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

51125638464 is a wasteful number, since it uses less digits than its factorization.

51125638464 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 798 (or 785 counting only the distinct ones).

The product of its digits is 691200, while the sum is 45.

The spelling of 51125638464 in words is "fifty-one billion, one hundred twenty-five million, six hundred thirty-eight thousand, four hundred sixty-four".