398765641 has 2 divisors, whose sum is σ = 398765642. Its totient is φ = 398765640.

The previous prime is 398765623. The next prime is 398765669. The reversal of 398765641 is 146567893.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 384356025 + 14409616 = 19605^2 + 3796^2 .

It is a cyclic number.

It is not a de Polignac number, because 398765641 - 2¹³ = 398757449 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (398765611) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199382820 + 199382821.

It is an arithmetic number, because the mean of its divisors is an integer number (199382821).

Almost surely, 2^398765641 is an apocalyptic number.

It is an amenable number.

398765641 is a deficient number, since it is larger than the sum of its proper divisors (1).

398765641 is an equidigital number, since it uses as much as digits as its factorization.

398765641 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1088640, while the sum is 49.

The square root of 398765641 is about 19969.1171812877. The cubic root of 398765641 is about 736.0476158791.

The spelling of 398765641 in words is "three hundred ninety-eight million, seven hundred sixty-five thousand, six hundred forty-one".