51320355840 has 1056 divisors, whose sum is σ = 210299281920. Its totient is φ = 11896160256.

The previous prime is 51320355817. The next prime is 51320355851. The reversal of 51320355840 is 4855302315.

51320355840 is a `hidden beast` number, since 51 + 3 + 20 + 3 + 5 + 584 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 51320355795 and 51320355804.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 307307437 + ... + 307307603.

Almost surely, 2^51320355840 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 51320355840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (105149640960).

51320355840 is an abundant number, since it is smaller than the sum of its proper divisors (158978926080).

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

51320355840 is a wasteful number, since it uses less digits than its factorization.

51320355840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239 (or 209 counting only the distinct ones).

The product of its (nonzero) digits is 72000, while the sum is 36.

The spelling of 51320355840 in words is "fifty-one billion, three hundred twenty million, three hundred fifty-five thousand, eight hundred forty".