398864 has 20 divisors (see below), whose sum is σ = 783804. Its totient is φ = 196608.

The previous prime is 398863. The next prime is 398887. The reversal of 398864 is 468893.

It can be written as a sum of positive squares in 2 ways, for example, as 313600 + 85264 = 560^2 + 292^2 .

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is not an unprimeable number, because it can be changed into a prime (398863) 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, 1424 + ... + 1680.

2³⁹⁸⁸⁶⁴ is an apocalyptic number.

It is an amenable number.

398864 is a deficient number, since it is larger than the sum of its proper divisors (384940).

398864 is a wasteful number, since it uses less digits than its factorization.

398864 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 362 (or 356 counting only the distinct ones).

The product of its digits is 41472, while the sum is 38.

The square root of 398864 is about 631.5568066295. The cubic root of 398864 is about 73.6108128411.

It can be divided in two parts, 39 and 8864, that multiplied together give a triangular number (345696 = T₈₃₁).

The spelling of 398864 in words is "three hundred ninety-eight thousand, eight hundred sixty-four".