51891736320 has 648 divisors, whose sum is σ = 192621278304. Its totient is φ = 13383180288.

The previous prime is 51891736277. The next prime is 51891736339. The reversal of 51891736320 is 2363719815.

51891736320 is a `hidden beast` number, since 5 + 1 + 8 + 9 + 1 + 7 + 3 + 632 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (648).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 71 ways as a sum of consecutive naturals, for example, 310728877 + ... + 310729043.

Almost surely, 2^51891736320 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 51891736320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96310639152).

51891736320 is an abundant number, since it is smaller than the sum of its proper divisors (140729541984).

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

51891736320 is an frugal number, since it uses more digits than its factorization.

51891736320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 249 (or 214 counting only the distinct ones).

The product of its (nonzero) digits is 272160, while the sum is 45.

The spelling of 51891736320 in words is "fifty-one billion, eight hundred ninety-one million, seven hundred thirty-six thousand, three hundred twenty".