51361661616 has 20 divisors (see below), whose sum is σ = 132684292632. Its totient is φ = 17120553856.

The previous prime is 51361661609. The next prime is 51361661639. The reversal of 51361661616 is 61616616315.

51361661616 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 535017261 + ... + 535017356.

Almost surely, 2^51361661616 is an apocalyptic number.

It is an amenable number.

51361661616 is an abundant number, since it is smaller than the sum of its proper divisors (81322631016).

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

51361661616 is a wasteful number, since it uses less digits than its factorization.

51361661616 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1070034628 (or 1070034622 counting only the distinct ones).

The product of its digits is 116640, while the sum is 42.

The spelling of 51361661616 in words is "fifty-one billion, three hundred sixty-one million, six hundred sixty-one thousand, six hundred sixteen".