398684 has 48 divisors (see below), whose sum is σ = 889056. Its totient is φ = 153600.

The previous prime is 398683. The next prime is 398693. The reversal of 398684 is 486893.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 398684.

It is not an unprimeable number, because it can be changed into a prime (398681) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9704 + ... + 9744.

It is an arithmetic number, because the mean of its divisors is an integer number (18522).

2³⁹⁸⁶⁸⁴ is an apocalyptic number.

398684 is a gapful number since it is divisible by the number (34) formed by its first and last digit.

It is an amenable number.

398684 is an abundant number, since it is smaller than the sum of its proper divisors (490372).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

398684 is a wasteful number, since it uses less digits than its factorization.

398684 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86 (or 84 counting only the distinct ones).

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

The square root of 398684 is about 631.4142855527. The cubic root of 398684 is about 73.5997381056.

Subtracting 398684 from its reverse (486893), we obtain a square (88209 = 297²).

The spelling of 398684 in words is "three hundred ninety-eight thousand, six hundred eighty-four".