165651661612133 has 8 divisors (see below), whose sum is σ = 175397176923480. Its totient is φ = 155906290736640.

The previous prime is 165651661612121. The next prime is 165651661612147. The reversal of 165651661612133 is 331216166156561.

It can be written as a sum of positive squares in 4 ways, for example, as 135597221522884 + 30054440089249 = 11644622^2 + 5482193^2 .

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 165651661612133 - 2²⁸ = 165651393176677 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 (165651661612153) 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, 33743288 + ... + 38339441.

It is an arithmetic number, because the mean of its divisors is an integer number (21924647115435).

Almost surely, 2^{165651661612133} is an apocalyptic number.

It is an amenable number.

165651661612133 is a deficient number, since it is larger than the sum of its proper divisors (9745515311347).

165651661612133 is a wasteful number, since it uses less digits than its factorization.

165651661612133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 72217927.

The product of its digits is 3499200, while the sum is 53.

The spelling of 165651661612133 in words is "one hundred sixty-five trillion, six hundred fifty-one billion, six hundred sixty-one million, six hundred twelve thousand, one hundred thirty-three".