51569778816 has 192 divisors, whose sum is σ = 154389362400. Its totient is φ = 17134571520.

The previous prime is 51569778809. The next prime is 51569778847. The reversal of 51569778816 is 61887796515.

51569778816 is a `hidden beast` number, since 51 + 569 + 7 + 7 + 8 + 8 + 16 = 666.

It is a tau number, because it is divible by the number of its divisors (192).

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 10292920 + ... + 10297928.

Almost surely, 2^51569778816 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 51569778816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (77194681200).

51569778816 is an abundant number, since it is smaller than the sum of its proper divisors (102819583584).

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

51569778816 is an equidigital number, since it uses as much as digits as its factorization.

51569778816 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5369 (or 5345 counting only the distinct ones).

The product of its digits is 25401600, while the sum is 63.

The spelling of 51569778816 in words is "fifty-one billion, five hundred sixty-nine million, seven hundred seventy-eight thousand, eight hundred sixteen".