165215122135645 has 4 divisors (see below), whose sum is σ = 198258146562780. Its totient is φ = 132172097708512.

The previous prime is 165215122135579. The next prime is 165215122135669. The reversal of 165215122135645 is 546531221512561.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 90733492820569 + 74481629315076 = 9525413^2 + 8630274^2 .

It is a cyclic number.

It is not a de Polignac number, because 165215122135645 - 2⁷ = 165215122135517 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16521512213560 + ... + 16521512213569.

It is an arithmetic number, because the mean of its divisors is an integer number (49564536640695).

Almost surely, 2^{165215122135645} is an apocalyptic number.

It is an amenable number.

165215122135645 is a deficient number, since it is larger than the sum of its proper divisors (33043024427135).

165215122135645 is an equidigital number, since it uses as much as digits as its factorization.

165215122135645 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33043024427134.

The product of its digits is 2160000, while the sum is 49.

The spelling of 165215122135645 in words is "one hundred sixty-five trillion, two hundred fifteen billion, one hundred twenty-two million, one hundred thirty-five thousand, six hundred forty-five".