51216666720012 has 36 divisors (see below), whose sum is σ = 132963388530336. Its totient is φ = 16610810827680.

The previous prime is 51216666720007. The next prime is 51216666720013. The reversal of 51216666720012 is 21002766661215.

It is a tau number, because it is divible by the number of its divisors (36).

It is a self number, because there is not a number n which added to its sum of digits gives 51216666720012.

It is not an unprimeable number, because it can be changed into a prime (51216666720013) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 19225474164 + ... + 19225476827.

It is an arithmetic number, because the mean of its divisors is an integer number (3693427459176).

Almost surely, 2^{51216666720012} is an apocalyptic number.

It is an amenable number.

51216666720012 is an abundant number, since it is smaller than the sum of its proper divisors (81746721810324).

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

51216666720012 is a wasteful number, since it uses less digits than its factorization.

51216666720012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 38450951038 (or 38450951033 counting only the distinct ones).

The product of its (nonzero) digits is 362880, while the sum is 45.

The spelling of 51216666720012 in words is "fifty-one trillion, two hundred sixteen billion, six hundred sixty-six million, seven hundred twenty thousand, twelve".