165611075501 has 2 divisors, whose sum is σ = 165611075502. Its totient is φ = 165611075500.

The previous prime is 165611075471. The next prime is 165611075521. The reversal of 165611075501 is 105570116561.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 163511053225 + 2100022276 = 404365^2 + 45826^2 .

It is a cyclic number.

It is not a de Polignac number, because 165611075501 - 2³⁰ = 164537333677 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (165611075521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82805537750 + 82805537751.

It is an arithmetic number, because the mean of its divisors is an integer number (82805537751).

Almost surely, 2^165611075501 is an apocalyptic number.

It is an amenable number.

165611075501 is a deficient number, since it is larger than the sum of its proper divisors (1).

165611075501 is an equidigital number, since it uses as much as digits as its factorization.

165611075501 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31500, while the sum is 38.

The spelling of 165611075501 in words is "one hundred sixty-five billion, six hundred eleven million, seventy-five thousand, five hundred one".