51491635200 has 570 divisors, whose sum is σ = 192726852626. Its totient is φ = 13589544960.

The previous prime is 51491635171. The next prime is 51491635277. The reversal of 51491635200 is 253619415.

51491635200 is a `hidden beast` number, since 5 + 14 + 9 + 1 + 635 + 2 + 0 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 2569273344 + 48922361856 = 50688^2 + 221184^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 530841552 + ... + 530841648.

Almost surely, 2^51491635200 is an apocalyptic number.

51491635200 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 51491635200, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96363426313).

51491635200 is an abundant number, since it is smaller than the sum of its proper divisors (141235217426).

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

51491635200 is an frugal number, since it uses more digits than its factorization.

51491635200 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 155 (or 107 counting only the distinct ones).

The product of its (nonzero) digits is 32400, while the sum is 36.

The spelling of 51491635200 in words is "fifty-one billion, four hundred ninety-one million, six hundred thirty-five thousand, two hundred".