398131 has 4 divisors (see below), whose sum is σ = 399600. Its totient is φ = 396664.

The previous prime is 398129. The next prime is 398143. The reversal of 398131 is 131893.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 398131 - 2¹ = 398129 is a prime.

It is a super-2 number, since 2×398131² = 317016586322, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 398096 and 398105.

It is not an unprimeable number, because it can be changed into a prime (398171) 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, 196 + ... + 913.

It is an arithmetic number, because the mean of its divisors is an integer number (99900).

2³⁹⁸¹³¹ is an apocalyptic number.

398131 is a deficient number, since it is larger than the sum of its proper divisors (1469).

398131 is a wasteful number, since it uses less digits than its factorization.

398131 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1468.

The product of its digits is 648, while the sum is 25.

The square root of 398131 is about 630.9762277614. The cubic root of 398131 is about 73.5656931913.

It can be divided in two parts, 398 and 131, that added together give a square (529 = 23²).

The spelling of 398131 in words is "three hundred ninety-eight thousand, one hundred thirty-one".