61656550161 has 4 divisors (see below), whose sum is σ = 82208733552. Its totient is φ = 41104366772.

The previous prime is 61656550127. The next prime is 61656550201. The reversal of 61656550161 is 16105565616.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 61656550161 - 2⁶ = 61656550097 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61656650161) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10276091691 + ... + 10276091696.

It is an arithmetic number, because the mean of its divisors is an integer number (20552183388).

Almost surely, 2^61656550161 is an apocalyptic number.

It is an amenable number.

61656550161 is a deficient number, since it is larger than the sum of its proper divisors (20552183391).

61656550161 is a wasteful number, since it uses less digits than its factorization.

61656550161 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20552183390.

The product of its (nonzero) digits is 162000, while the sum is 42.

The spelling of 61656550161 in words is "sixty-one billion, six hundred fifty-six million, five hundred fifty thousand, one hundred sixty-one".