51661651116160 has 128 divisors (see below), whose sum is σ = 126752085048960. Its totient is φ = 20128142254080.

The previous prime is 51661651116139. The next prime is 51661651116161. The reversal of 51661651116160 is 6161115616615.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (128).

It is a self number, because there is not a number n which added to its sum of digits gives 51661651116160.

It is not an unprimeable number, because it can be changed into a prime (51661651116161) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3077397 + ... + 10620436.

It is an arithmetic number, because the mean of its divisors is an integer number (990250664445).

Almost surely, 2^{51661651116160} is an apocalyptic number.

It is an amenable number.

51661651116160 is an abundant number, since it is smaller than the sum of its proper divisors (75090433932800).

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

51661651116160 is a wasteful number, since it uses less digits than its factorization.

51661651116160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13698006 (or 13697994 counting only the distinct ones).

The product of its (nonzero) digits is 194400, while the sum is 46.

The spelling of 51661651116160 in words is "fifty-one trillion, six hundred sixty-one billion, six hundred fifty-one million, one hundred sixteen thousand, one hundred sixty".