51690864899520 has 1344 divisors, whose sum is σ = 234768677584896. Its totient is φ = 10512370667520.

The previous prime is 51690864899483. The next prime is 51690864899533. The reversal of 51690864899520 is 2599846809615.

51690864899520 is a `hidden beast` number, since 5 + 1 + 6 + 9 + 0 + 8 + 6 + 4 + 8 + 99 + 520 = 666.

It is a tau number, because it is divible by the number of its divisors (1344).

It is a Harshad number since it is a multiple of its sum of digits (72).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 281321599 + ... + 281505281.

It is an arithmetic number, because the mean of its divisors is an integer number (174679075584).

Almost surely, 2^{51690864899520} 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 51690864899520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (117384338792448).

51690864899520 is an abundant number, since it is smaller than the sum of its proper divisors (183077812685376).

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

51690864899520 is a wasteful number, since it uses less digits than its factorization.

51690864899520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 183780 (or 183758 counting only the distinct ones).

The product of its (nonzero) digits is 335923200, while the sum is 72.

The spelling of 51690864899520 in words is "fifty-one trillion, six hundred ninety billion, eight hundred sixty-four million, eight hundred ninety-nine thousand, five hundred twenty".