51681878160 has 640 divisors, whose sum is σ = 193235632128. Its totient is φ = 11374387200.

The previous prime is 51681878137. The next prime is 51681878189. The reversal of 51681878160 is 6187818615.

It is a Harshad number since it is a multiple of its sum of digits (51).

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 127 ways as a sum of consecutive naturals, for example, 168344727 + ... + 168345033.

Almost surely, 2^51681878160 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 51681878160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96617816064).

51681878160 is an abundant number, since it is smaller than the sum of its proper divisors (141553753968).

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

51681878160 is a wasteful number, since it uses less digits than its factorization.

51681878160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 404 (or 376 counting only the distinct ones).

The product of its (nonzero) digits is 645120, while the sum is 51.

The spelling of 51681878160 in words is "fifty-one billion, six hundred eighty-one million, eight hundred seventy-eight thousand, one hundred sixty".