51861898408320 has 3584 divisors, whose sum is σ = 251097152947200. Its totient is φ = 9887429099520.

The previous prime is 51861898408291. The next prime is 51861898408387. The reversal of 51861898408320 is 2380489816815.

51861898408320 is a `hidden beast` number, since 5 + 1 + 8 + 618 + 9 + 8 + 4 + 0 + 8 + 3 + 2 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (63).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 447 ways as a sum of consecutive naturals, for example, 136838781891 + ... + 136838782269.

It is an arithmetic number, because the mean of its divisors is an integer number (70060589550).

Almost surely, 2^{51861898408320} 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 51861898408320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (125548576473600).

51861898408320 is an abundant number, since it is smaller than the sum of its proper divisors (199235254538880).

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

51861898408320 is a wasteful number, since it uses less digits than its factorization.

51861898408320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 740 (or 713 counting only the distinct ones).

The product of its (nonzero) digits is 26542080, while the sum is 63.

The spelling of 51861898408320 in words is "fifty-one trillion, eight hundred sixty-one billion, eight hundred ninety-eight million, four hundred eight thousand, three hundred twenty".