51620440320 has 576 divisors, whose sum is σ = 194654208000. Its totient is φ = 12917366784.

The previous prime is 51620440271. The next prime is 51620440321. The reversal of 51620440320 is 2304402615.

51620440320 is a `hidden beast` number, since 5 + 1 + 620 + 4 + 4 + 0 + 32 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (576).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (51620440321) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 83392971 + ... + 83393589.

Almost surely, 2^51620440320 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 51620440320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (97327104000).

51620440320 is an abundant number, since it is smaller than the sum of its proper divisors (143033767680).

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

51620440320 is a wasteful number, since it uses less digits than its factorization.

51620440320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 795 (or 775 counting only the distinct ones).

The product of its (nonzero) digits is 5760, while the sum is 27.

Adding to 51620440320 its reverse (2304402615), we get a palindrome (53924842935).

The spelling of 51620440320 in words is "fifty-one billion, six hundred twenty million, four hundred forty thousand, three hundred twenty".