399340169 has 2 divisors, whose sum is σ = 399340170. Its totient is φ = 399340168.

The previous prime is 399340159. The next prime is 399340177. The reversal of 399340169 is 961043993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 361456144 + 37884025 = 19012^2 + 6155^2 .

It is a cyclic number.

It is not a de Polignac number, because 399340169 - 2¹⁶ = 399274633 is a prime.

It is a super-2 number, since 2×399340169² = 318945141153897122, which contains 22 as substring.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (399340129) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199670084 + 199670085.

It is an arithmetic number, because the mean of its divisors is an integer number (199670085).

Almost surely, 2^399340169 is an apocalyptic number.

It is an amenable number.

399340169 is a deficient number, since it is larger than the sum of its proper divisors (1).

399340169 is an equidigital number, since it uses as much as digits as its factorization.

399340169 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 157464, while the sum is 44.

The square root of 399340169 is about 19983.4974166185. The cubic root of 399340169 is about 736.4009370560.

The spelling of 399340169 in words is "three hundred ninety-nine million, three hundred forty thousand, one hundred sixty-nine".