398120309 has 2 divisors, whose sum is σ = 398120310. Its totient is φ = 398120308.

The previous prime is 398120299. The next prime is 398120347. The reversal of 398120309 is 903021893.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 246584209 + 151536100 = 15703^2 + 12310^2 .

It is a cyclic number.

It is not a de Polignac number, because 398120309 - 2²⁰ = 397071733 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398120389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199060154 + 199060155.

It is an arithmetic number, because the mean of its divisors is an integer number (199060155).

Almost surely, 2^398120309 is an apocalyptic number.

It is an amenable number.

398120309 is a deficient number, since it is larger than the sum of its proper divisors (1).

398120309 is an equidigital number, since it uses as much as digits as its factorization.

398120309 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 11664, while the sum is 35.

The square root of 398120309 is about 19952.9523880553. The cubic root of 398120309 is about 735.6503469959.

The spelling of 398120309 in words is "three hundred ninety-eight million, one hundred twenty thousand, three hundred nine".