51991328480 has 576 divisors, whose sum is σ = 167535490752. Its totient is φ = 15049359360.

The previous prime is 51991328447. The next prime is 51991328491. The reversal of 51991328480 is 8482319915.

51991328480 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 2×51991328480² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 64107275 + ... + 64108085.

It is an arithmetic number, because the mean of its divisors is an integer number (290860227).

Almost surely, 2^51991328480 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 51991328480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (83767745376).

51991328480 is an abundant number, since it is smaller than the sum of its proper divisors (115544162272).

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

51991328480 is a wasteful number, since it uses less digits than its factorization.

51991328480 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 907 (or 892 counting only the distinct ones).

The product of its (nonzero) digits is 622080, while the sum is 50.

The spelling of 51991328480 in words is "fifty-one billion, nine hundred ninety-one million, three hundred twenty-eight thousand, four hundred eighty".