51321483920 has 80 divisors (see below), whose sum is σ = 136755354240. Its totient is φ = 17546022912.

The previous prime is 51321483919. The next prime is 51321483929. The reversal of 51321483920 is 2938412315.

It is a tau number, because it is divible by the number of its divisors (80).

It is not an unprimeable number, because it can be changed into a prime (51321483929) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 67871 + ... + 327489.

It is an arithmetic number, because the mean of its divisors is an integer number (1709441928).

Almost surely, 2^51321483920 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 51321483920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68377677120).

51321483920 is an abundant number, since it is smaller than the sum of its proper divisors (85433870320).

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

51321483920 is a wasteful number, since it uses less digits than its factorization.

51321483920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 259992 (or 259986 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 38.

The spelling of 51321483920 in words is "fifty-one billion, three hundred twenty-one million, four hundred eighty-three thousand, nine hundred twenty".