198749 has 4 divisors (see below), whose sum is σ = 199836. Its totient is φ = 197664.

The previous prime is 198733. The next prime is 198761. The reversal of 198749 is 947891.

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 can be written as a sum of positive squares in 2 ways, for example, as 24025 + 174724 = 155^2 + 418^2 .

It is a cyclic number.

It is not a de Polignac number, because 198749 - 2⁴ = 198733 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198719) 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, 194 + ... + 659.

It is an arithmetic number, because the mean of its divisors is an integer number (49959).

2¹⁹⁸⁷⁴⁹ is an apocalyptic number.

It is an amenable number.

198749 is a deficient number, since it is larger than the sum of its proper divisors (1087).

198749 is an equidigital number, since it uses as much as digits as its factorization.

198749 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1086.

The product of its digits is 18144, while the sum is 38.

The square root of 198749 is about 445.8127409575. The cubic root of 198749 is about 58.3581681102.

The spelling of 198749 in words is "one hundred ninety-eight thousand, seven hundred forty-nine".