165044921 has 2 divisors, whose sum is σ = 165044922. Its totient is φ = 165044920.

The previous prime is 165044917. The next prime is 165044927. The reversal of 165044921 is 129440561.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 162205696 + 2839225 = 12736^2 + 1685^2 .

It is a cyclic number.

It is not a de Polignac number, because 165044921 - 2² = 165044917 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (165044927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82522460 + 82522461.

It is an arithmetic number, because the mean of its divisors is an integer number (82522461).

Almost surely, 2^165044921 is an apocalyptic number.

It is an amenable number.

165044921 is a deficient number, since it is larger than the sum of its proper divisors (1).

165044921 is an equidigital number, since it uses as much as digits as its factorization.

165044921 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 32.

The square root of 165044921 is about 12846.9810072250. The cubic root of 165044921 is about 548.5304250694.

The spelling of 165044921 in words is "one hundred sixty-five million, forty-four thousand, nine hundred twenty-one".