51247145664 has 896 divisors, whose sum is σ = 188767272960. Its totient is φ = 13412044800.

The previous prime is 51247145659. The next prime is 51247145683. The reversal of 51247145664 is 46654174215.

51247145664 is a `hidden beast` number, since 5 + 12 + 4 + 71 + 4 + 566 + 4 = 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 127 ways as a sum of consecutive naturals, for example, 403520769 + ... + 403520895.

It is an arithmetic number, because the mean of its divisors is an integer number (210677760).

Almost surely, 2^51247145664 is an apocalyptic number.

51247145664 is a gapful number since it is divisible by the number (54) 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 51247145664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94383636480).

51247145664 is an abundant number, since it is smaller than the sum of its proper divisors (137520127296).

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

51247145664 is a wasteful number, since it uses less digits than its factorization.

51247145664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 266 (or 250 counting only the distinct ones).

The product of its digits is 806400, while the sum is 45.

The spelling of 51247145664 in words is "fifty-one billion, two hundred forty-seven million, one hundred forty-five thousand, six hundred sixty-four".