51531531264 has 330 divisors, whose sum is σ = 162502982334. Its totient is φ = 16263659520.

The previous prime is 51531531187. The next prime is 51531531307. The reversal of 51531531264 is 46213513515.

51531531264 is a `hidden beast` number, since 5 + 1 + 531 + 53 + 12 + 64 = 666.

It can be written as a sum of positive squares in only one way, i.e., 47908454400 + 3623076864 = 218880^2 + 60192^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 29941924 + ... + 29943644.

Almost surely, 2^51531531264 is an apocalyptic number.

51531531264 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 51531531264, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (81251491167).

51531531264 is an abundant number, since it is smaller than the sum of its proper divisors (110971451070).

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

51531531264 is a wasteful number, since it uses less digits than its factorization.

51531531264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1791 (or 1745 counting only the distinct ones).

The product of its digits is 54000, while the sum is 36.

The spelling of 51531531264 in words is "fifty-one billion, five hundred thirty-one million, five hundred thirty-one thousand, two hundred sixty-four".