51640610400 has 252 divisors, whose sum is σ = 189017128692. Its totient is φ = 13770673920.

The previous prime is 51640610383. The next prime is 51640610429. The reversal of 51640610400 is 401604615.

51640610400 is a `hidden beast` number, since 5 + 1 + 6 + 4 + 0 + 610 + 40 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 41 ways as a sum of consecutive naturals, for example, 538927 + ... + 627473.

It is an arithmetic number, because the mean of its divisors is an integer number (750067971).

Almost surely, 2^51640610400 is an apocalyptic number.

51640610400 is a gapful number since it is divisible by the number (50) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51640610400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94508564346).

51640610400 is an abundant number, since it is smaller than the sum of its proper divisors (137376518292).

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

51640610400 is an equidigital number, since it uses as much as digits as its factorization.

51640610400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 88585 (or 88557 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 27.

The spelling of 51640610400 in words is "fifty-one billion, six hundred forty million, six hundred ten thousand, four hundred".