61666121165 has 48 divisors (see below), whose sum is σ = 84529267200. Its totient is φ = 43108137600.

The previous prime is 61666121149. The next prime is 61666121183. The reversal of 61666121165 is 56112166616.

It is not a de Polignac number, because 61666121165 - 2⁴ = 61666121149 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2783462 + ... + 2805528.

It is an arithmetic number, because the mean of its divisors is an integer number (1761026400).

Almost surely, 2^61666121165 is an apocalyptic number.

It is an amenable number.

61666121165 is a deficient number, since it is larger than the sum of its proper divisors (22863146035).

61666121165 is a wasteful number, since it uses less digits than its factorization.

61666121165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22274 (or 22263 counting only the distinct ones).

The product of its digits is 77760, while the sum is 41.

The spelling of 61666121165 in words is "sixty-one billion, six hundred sixty-six million, one hundred twenty-one thousand, one hundred sixty-five".