66161610501605 has 8 divisors (see below), whose sum is σ = 79407962311200. Its totient is φ = 52919935261776.

The previous prime is 66161610501601. The next prime is 66161610501677. The reversal of 66161610501605 is 50610501616166.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 66161610501605 - 2² = 66161610501601 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66161610501601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1169111315 + ... + 1169167904.

It is an arithmetic number, because the mean of its divisors is an integer number (9925995288900).

Almost surely, 2^{66161610501605} is an apocalyptic number.

It is an amenable number.

66161610501605 is a deficient number, since it is larger than the sum of its proper divisors (13246351809595).

66161610501605 is a wasteful number, since it uses less digits than its factorization.

66161610501605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2338284883.

The product of its (nonzero) digits is 194400, while the sum is 44.

The spelling of 66161610501605 in words is "sixty-six trillion, one hundred sixty-one billion, six hundred ten million, five hundred one thousand, six hundred five".