398917 has 2 divisors, whose sum is σ = 398918. Its totient is φ = 398916.

The previous prime is 398903. The next prime is 398921. The reversal of 398917 is 719893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 312481 + 86436 = 559^2 + 294^2 .

It is an emirp because it is prime and its reverse (719893) is a distict prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-398917 is a prime.

It is a nialpdrome in base 14.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (398977) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199458 + 199459.

It is an arithmetic number, because the mean of its divisors is an integer number (199459).

2³⁹⁸⁹¹⁷ is an apocalyptic number.

It is an amenable number.

398917 is a deficient number, since it is larger than the sum of its proper divisors (1).

398917 is an equidigital number, since it uses as much as digits as its factorization.

398917 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13608, while the sum is 37.

The square root of 398917 is about 631.5987650400. The cubic root of 398917 is about 73.6140731005.

The spelling of 398917 in words is "three hundred ninety-eight thousand, nine hundred seventeen".