165101561 has 2 divisors, whose sum is σ = 165101562. Its totient is φ = 165101560.

The previous prime is 165101551. The next prime is 165101597.

165101561 is nontrivially palindromic in base 10.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 164968336 + 133225 = 12844^2 + 365^2 .

It is a palprime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165101561 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 165101561.

It is not a weakly prime, because it can be changed into another prime (165101551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82550780 + 82550781.

It is an arithmetic number, because the mean of its divisors is an integer number (82550781).

Almost surely, 2^165101561 is an apocalyptic number.

It is an amenable number.

165101561 is a deficient number, since it is larger than the sum of its proper divisors (1).

165101561 is an equidigital number, since it uses as much as digits as its factorization.

165101561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 900, while the sum is 26.

The square root of 165101561 is about 12849.1852270874. The cubic root of 165101561 is about 548.5931659881.

The spelling of 165101561 in words is "one hundred sixty-five million, one hundred one thousand, five hundred sixty-one".