398543917 has 2 divisors, whose sum is σ = 398543918. Its totient is φ = 398543916.

The previous prime is 398543891. The next prime is 398543921. The reversal of 398543917 is 719345893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 263542756 + 135001161 = 16234^2 + 11619^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-398543917 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 (398543947) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199271958 + 199271959.

It is an arithmetic number, because the mean of its divisors is an integer number (199271959).

Almost surely, 2^398543917 is an apocalyptic number.

It is an amenable number.

398543917 is a deficient number, since it is larger than the sum of its proper divisors (1).

398543917 is an equidigital number, since it uses as much as digits as its factorization.

398543917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 816480, while the sum is 49.

The square root of 398543917 is about 19963.5647367899. The cubic root of 398543917 is about 735.9111700892.

The spelling of 398543917 in words is "three hundred ninety-eight million, five hundred forty-three thousand, nine hundred seventeen".