51565550400 has 1008 divisors, whose sum is σ = 232856227200. Its totient is φ = 10868981760.

The previous prime is 51565550363. The next prime is 51565550453. The reversal of 51565550400 is 405556515.

51565550400 is a `hidden beast` number, since 5 + 1 + 5 + 65 + 550 + 40 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (1008).

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

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 51105096 + ... + 51106104.

Almost surely, 2^51565550400 is an apocalyptic number.

51565550400 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 51565550400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (116428113600).

51565550400 is an abundant number, since it is smaller than the sum of its proper divisors (181290676800).

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

51565550400 is a wasteful number, since it uses less digits than its factorization.

51565550400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1073 (or 1039 counting only the distinct ones).

The product of its (nonzero) digits is 75000, while the sum is 36.

The spelling of 51565550400 in words is "fifty-one billion, five hundred sixty-five million, five hundred fifty thousand, four hundred".