51265218816 has 360 divisors, whose sum is σ = 180352617984. Its totient is φ = 14173470720.

The previous prime is 51265218791. The next prime is 51265218833. The reversal of 51265218816 is 61881256215.

51265218816 is a `hidden beast` number, since 512 + 6 + 52 + 1 + 8 + 81 + 6 = 666.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 4494016 + ... + 4505408.

Almost surely, 2^51265218816 is an apocalyptic number.

51265218816 is a gapful number since it is divisible by the number (56) 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 51265218816, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (90176308992).

51265218816 is an abundant number, since it is smaller than the sum of its proper divisors (129087399168).

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

51265218816 is a wasteful number, since it uses less digits than its factorization.

51265218816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11459 (or 11436 counting only the distinct ones).

The product of its digits is 230400, while the sum is 45.

The spelling of 51265218816 in words is "fifty-one billion, two hundred sixty-five million, two hundred eighteen thousand, eight hundred sixteen".