51661565116101 has 6 divisors (see below), whose sum is σ = 74622260723270. Its totient is φ = 34441043410728.

The previous prime is 51661565116067. The next prime is 51661565116103. The reversal of 51661565116101 is 10161156516615.

51661565116101 is a `hidden beast` number, since 5 + 1 + 6 + 6 + 15 + 6 + 5 + 11 + 610 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 47494357308225 + 4167207807876 = 6891615^2 + 2041374^2 .

It is not a de Polignac number, because 51661565116101 - 2⁷ = 51661565115973 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (51661565116103) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2870086950886 + ... + 2870086950903.

Almost surely, 2^{51661565116101} is an apocalyptic number.

It is an amenable number.

51661565116101 is a deficient number, since it is larger than the sum of its proper divisors (22960695607169).

51661565116101 is a wasteful number, since it uses less digits than its factorization.

51661565116101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5740173901795 (or 5740173901792 counting only the distinct ones).

The product of its (nonzero) digits is 162000, while the sum is 45.

The spelling of 51661565116101 in words is "fifty-one trillion, six hundred sixty-one billion, five hundred sixty-five million, one hundred sixteen thousand, one hundred one".