51561716500 has 96 divisors (see below), whose sum is σ = 130249357056. Its totient is φ = 17465212800.

The previous prime is 51561716483. The next prime is 51561716513. The reversal of 51561716500 is 561716515.

It is a super-2 number, since 2×51561716500² (a number of 22 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 51561716500.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 201754 + ... + 379246.

It is an arithmetic number, because the mean of its divisors is an integer number (1356764136).

Almost surely, 2^51561716500 is an apocalyptic number.

51561716500 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 51561716500, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (65124678528).

51561716500 is an abundant number, since it is smaller than the sum of its proper divisors (78687640556).

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

51561716500 is a wasteful number, since it uses less digits than its factorization.

51561716500 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 177602 (or 177590 counting only the distinct ones).

The product of its (nonzero) digits is 31500, while the sum is 37.

The spelling of 51561716500 in words is "fifty-one billion, five hundred sixty-one million, seven hundred sixteen thousand, five hundred".