51868887840 has 480 divisors, whose sum is σ = 228227497344. Its totient is φ = 10777743360.

The previous prime is 51868887803. The next prime is 51868887871. The reversal of 51868887840 is 4878886815.

51868887840 is a `hidden beast` number, since 518 + 6 + 8 + 8 + 8 + 78 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (480).

It is a Harshad number since it is a multiple of its sum of digits (63).

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 79 ways as a sum of consecutive naturals, for example, 971932 + ... + 1023908.

Almost surely, 2^51868887840 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 51868887840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (114113748672).

51868887840 is an abundant number, since it is smaller than the sum of its proper divisors (176358609504).

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

51868887840 is a wasteful number, since it uses less digits than its factorization.

51868887840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 52022 (or 52005 counting only the distinct ones).

The product of its (nonzero) digits is 27525120, while the sum is 63.

The spelling of 51868887840 in words is "fifty-one billion, eight hundred sixty-eight million, eight hundred eighty-seven thousand, eight hundred forty".