399769 has 2 divisors, whose sum is σ = 399770. Its totient is φ = 399768.

The previous prime is 399761. The next prime is 399781. The reversal of 399769 is 967993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 250000 + 149769 = 500^2 + 387^2 .

It is a cyclic number.

It is not a de Polignac number, because 399769 - 2³ = 399761 is a prime.

It is a super-2 number, since 2×399769² = 319630506722, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199884 + 199885.

It is an arithmetic number, because the mean of its divisors is an integer number (199885).

2³⁹⁹⁷⁶⁹ is an apocalyptic number.

It is an amenable number.

399769 is a deficient number, since it is larger than the sum of its proper divisors (1).

399769 is an equidigital number, since it uses as much as digits as its factorization.

399769 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 91854, while the sum is 43.

The square root of 399769 is about 632.2728841252. The cubic root of 399769 is about 73.6664437203. Note that the first 3 decimals are identical.

The spelling of 399769 in words is "three hundred ninety-nine thousand, seven hundred sixty-nine".