51656459400 has 768 divisors, whose sum is σ = 226118860800. Its totient is φ = 10544256000.

The previous prime is 51656459389. The next prime is 51656459411. The reversal of 51656459400 is 495465615.

51656459400 is a `hidden beast` number, since 5 + 1 + 6 + 56 + 4 + 594 + 0 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (51656459389) and next prime (51656459411).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 15231705 + ... + 15235095.

It is an arithmetic number, because the mean of its divisors is an integer number (294425600).

Almost surely, 2^51656459400 is an apocalyptic number.

51656459400 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 51656459400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113059430400).

51656459400 is an abundant number, since it is smaller than the sum of its proper divisors (174462401400).

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

51656459400 is a wasteful number, since it uses less digits than its factorization.

51656459400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3467 (or 3452 counting only the distinct ones).

The product of its (nonzero) digits is 648000, while the sum is 45.

The spelling of 51656459400 in words is "fifty-one billion, six hundred fifty-six million, four hundred fifty-nine thousand, four hundred".