198731 has 4 divisors (see below), whose sum is σ = 214032. Its totient is φ = 183432.

The previous prime is 198719. The next prime is 198733. The reversal of 198731 is 137891.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 137891 = 13 ⋅10607.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198731 is a prime.

It is a super-2 number, since 2×198731² = 78988020722, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 198694 and 198703.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198733) 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 in 3 ways as a sum of consecutive naturals, for example, 7631 + ... + 7656.

It is an arithmetic number, because the mean of its divisors is an integer number (53508).

2¹⁹⁸⁷³¹ is an apocalyptic number.

198731 is a deficient number, since it is larger than the sum of its proper divisors (15301).

198731 is a wasteful number, since it uses less digits than its factorization.

198731 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15300.

The product of its digits is 1512, while the sum is 29.

The square root of 198731 is about 445.7925526520. The cubic root of 198731 is about 58.3564062921.

It can be divided in two parts, 198 and 731, that added together give a palindrome (929).

The spelling of 198731 in words is "one hundred ninety-eight thousand, seven hundred thirty-one".