165979321 has 2 divisors, whose sum is σ = 165979322. Its totient is φ = 165979320.

The previous prime is 165979291. The next prime is 165979343. The reversal of 165979321 is 123979561.

165979321 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 144865296 + 21114025 = 12036^2 + 4595^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-165979321 is a prime.

It is not a weakly prime, because it can be changed into another prime (165977321) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 82989660 + 82989661.

It is an arithmetic number, because the mean of its divisors is an integer number (82989661).

Almost surely, 2^165979321 is an apocalyptic number.

It is an amenable number.

165979321 is a deficient number, since it is larger than the sum of its proper divisors (1).

165979321 is an equidigital number, since it uses as much as digits as its factorization.

165979321 is an evil number, because the sum of its binary digits is even.

The product of its digits is 102060, while the sum is 43.

The square root of 165979321 is about 12883.2962008952. The cubic root of 165979321 is about 549.5636439804.

The spelling of 165979321 in words is "one hundred sixty-five million, nine hundred seventy-nine thousand, three hundred twenty-one".