51615871816320 has 1024 divisors, whose sum is σ = 218262739968000. Its totient is φ = 11271616266240.

The previous prime is 51615871816307. The next prime is 51615871816391. The reversal of 51615871816320 is 2361817851615.

51615871816320 is a `hidden beast` number, since 5 + 1 + 6 + 1 + 587 + 18 + 16 + 32 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 2451001951 + ... + 2451023009.

It is an arithmetic number, because the mean of its divisors is an integer number (213147207000).

Almost surely, 2^{51615871816320} 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 51615871816320, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (109131369984000).

51615871816320 is an abundant number, since it is smaller than the sum of its proper divisors (166646868151680).

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

51615871816320 is a wasteful number, since it uses less digits than its factorization.

51615871816320 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21998 (or 21980 counting only the distinct ones).

The product of its (nonzero) digits is 2419200, while the sum is 54.

The spelling of 51615871816320 in words is "fifty-one trillion, six hundred fifteen billion, eight hundred seventy-one million, eight hundred sixteen thousand, three hundred twenty".