198931 has 4 divisors (see below), whose sum is σ = 199864. Its totient is φ = 198000.

The previous prime is 198929. The next prime is 198937. The reversal of 198931 is 139891.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 198931 - 2¹ = 198929 is a prime.

It is a super-2 number, since 2×198931² = 79147085522, 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 = 198893 and 198902.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198937) 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, 31 + ... + 631.

It is an arithmetic number, because the mean of its divisors is an integer number (49966).

2¹⁹⁸⁹³¹ is an apocalyptic number.

198931 is a deficient number, since it is larger than the sum of its proper divisors (933).

198931 is an equidigital number, since it uses as much as digits as its factorization.

198931 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 932.

The product of its digits is 1944, while the sum is 31.

The square root of 198931 is about 446.0168158265. The cubic root of 198931 is about 58.3759760760.

The spelling of 198931 in words is "one hundred ninety-eight thousand, nine hundred thirty-one".