51519686400 has 648 divisors, whose sum is σ = 226723995680. Its totient is φ = 10868981760.

The previous prime is 51519686399. The next prime is 51519686401. The reversal of 51519686400 is 468691515.

51519686400 is a `hidden beast` number, since 5 + 151 + 96 + 8 + 6 + 400 = 666.

It is an interprime number because it is at equal distance from previous prime (51519686399) and next prime (51519686401).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51519686401) by changing a digit.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 5236686 + ... + 5246514.

Almost surely, 2^51519686400 is an apocalyptic number.

51519686400 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 51519686400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113361997840).

51519686400 is an abundant number, since it is smaller than the sum of its proper divisors (175204309280).

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

51519686400 is a wasteful number, since it uses less digits than its factorization.

51519686400 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9881 (or 9859 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 45.

The spelling of 51519686400 in words is "fifty-one billion, five hundred nineteen million, six hundred eighty-six thousand, four hundred".