398857 has 2 divisors, whose sum is σ = 398858. Its totient is φ = 398856.

The previous prime is 398833. The next prime is 398863. The reversal of 398857 is 758893.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 331776 + 67081 = 576^2 + 259^2 .

It is an emirp because it is prime and its reverse (758893) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 398857 - 2⁷ = 398729 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (398887) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199428 + 199429.

It is an arithmetic number, because the mean of its divisors is an integer number (199429).

2³⁹⁸⁸⁵⁷ is an apocalyptic number.

It is an amenable number.

398857 is a deficient number, since it is larger than the sum of its proper divisors (1).

398857 is an equidigital number, since it uses as much as digits as its factorization.

398857 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 60480, while the sum is 40.

The square root of 398857 is about 631.5512647442. The cubic root of 398857 is about 73.6103822192.

The spelling of 398857 in words is "three hundred ninety-eight thousand, eight hundred fifty-seven".