398999 has 4 divisors (see below), whose sum is σ = 401280. Its totient is φ = 396720.

The previous prime is 398989. The next prime is 399023. The reversal of 398999 is 999893.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 999893 = 71 ⋅14083.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-398999 is a prime.

It is a Duffinian number.

398999 is a modest number, since divided by 999 gives 398 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (398969) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 854 + ... + 1235.

It is an arithmetic number, because the mean of its divisors is an integer number (100320).

2³⁹⁸⁹⁹⁹ is an apocalyptic number.

398999 is a deficient number, since it is larger than the sum of its proper divisors (2281).

398999 is a wasteful number, since it uses less digits than its factorization.

398999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2280.

The product of its digits is 157464, while the sum is 47.

The square root of 398999 is about 631.6636763342. The cubic root of 398999 is about 73.6191167064.

The spelling of 398999 in words is "three hundred ninety-eight thousand, nine hundred ninety-nine".