51521239380 has 192 divisors, whose sum is σ = 164786952960. Its totient is φ = 11914960896.

The previous prime is 51521239379. The next prime is 51521239403. The reversal of 51521239380 is 8393212515.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 8204802 + ... + 8211078.

It is an arithmetic number, because the mean of its divisors is an integer number (858265380).

Almost surely, 2^51521239380 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 51521239380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (82393476480).

51521239380 is an abundant number, since it is smaller than the sum of its proper divisors (113265713580).

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

51521239380 is a wasteful number, since it uses less digits than its factorization.

51521239380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6938 (or 6936 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 39.

The spelling of 51521239380 in words is "fifty-one billion, five hundred twenty-one million, two hundred thirty-nine thousand, three hundred eighty".