51720670612156 has 72 divisors (see below), whose sum is σ = 113409546699120. Its totient is φ = 20456968670208.

The previous prime is 51720670612123. The next prime is 51720670612187. The reversal of 51720670612156 is 65121607602715.

It is a super-2 number, since 2×51720670612156² (a number of 28 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 11236396 + ... + 15155788.

Almost surely, 2^{51720670612156} 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 51720670612156, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56704773349560).

51720670612156 is an abundant number, since it is smaller than the sum of its proper divisors (61688876086964).

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

51720670612156 is a wasteful number, since it uses less digits than its factorization.

51720670612156 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3924603 (or 3924594 counting only the distinct ones).

The product of its (nonzero) digits is 1058400, while the sum is 49.

The spelling of 51720670612156 in words is "fifty-one trillion, seven hundred twenty billion, six hundred seventy million, six hundred twelve thousand, one hundred fifty-six".