51320533440 has 336 divisors, whose sum is σ = 181294210944. Its totient is φ = 12289136640.

The previous prime is 51320533379. The next prime is 51320533441. The reversal of 51320533440 is 4433502315.

51320533440 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 51320533398 and 51320533407.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51320533441) by changing a digit.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 9638619 + ... + 9643941.

It is an arithmetic number, because the mean of its divisors is an integer number (539566104).

Almost surely, 2^51320533440 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 51320533440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90647105472).

51320533440 is an abundant number, since it is smaller than the sum of its proper divisors (129973677504).

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

51320533440 is a wasteful number, since it uses less digits than its factorization.

51320533440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5448 (or 5427 counting only the distinct ones).

The product of its (nonzero) digits is 21600, while the sum is 30.

It can be divided in two parts, 513205 and 33440, that added together give a palindrome (546645).

The spelling of 51320533440 in words is "fifty-one billion, three hundred twenty million, five hundred thirty-three thousand, four hundred forty".