51391972800 has 1008 divisors, whose sum is σ = 226172524032. Its totient is φ = 11222323200.

The previous prime is 51391972799. The next prime is 51391972889. The reversal of 51391972800 is 827919315.

It is a tau number, because it is divible by the number of its divisors (1008).

It is a super-2 number, since 2×51391972800² (a number of 22 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 62596390 + ... + 62597210.

It is an arithmetic number, because the mean of its divisors is an integer number (224377504).

Almost surely, 2^51391972800 is an apocalyptic number.

51391972800 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51391972800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113086262016).

51391972800 is an abundant number, since it is smaller than the sum of its proper divisors (174780551232).

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

51391972800 is a wasteful number, since it uses less digits than its factorization.

51391972800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 888 (or 861 counting only the distinct ones).

The product of its (nonzero) digits is 136080, while the sum is 45.

The spelling of 51391972800 in words is "fifty-one billion, three hundred ninety-one million, nine hundred seventy-two thousand, eight hundred".