51005388720 has 640 divisors, whose sum is σ = 193523613696. Its totient is φ = 10944000000.

The previous prime is 51005388701. The next prime is 51005388727. The reversal of 51005388720 is 2788350015.

It is a hoax number, since the sum of its digits (39) coincides with the sum of the digits of its distinct prime factors.

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

It is not an unprimeable number, because it can be changed into a prime (51005388727) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 203208595 + ... + 203208845.

Almost surely, 2^51005388720 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 51005388720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96761806848).

51005388720 is an abundant number, since it is smaller than the sum of its proper divisors (142518224976).

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

51005388720 is a wasteful number, since it uses less digits than its factorization.

51005388720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 513 (or 507 counting only the distinct ones).

The product of its (nonzero) digits is 67200, while the sum is 39.

The spelling of 51005388720 in words is "fifty-one billion, five million, three hundred eighty-eight thousand, seven hundred twenty".