198521 has 4 divisors (see below), whose sum is σ = 201552. Its totient is φ = 195492.

The previous prime is 198503. The next prime is 198529. The reversal of 198521 is 125891.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-198521 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198529) 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, 1415 + ... + 1548.

It is an arithmetic number, because the mean of its divisors is an integer number (50388).

2¹⁹⁸⁵²¹ is an apocalyptic number.

It is an amenable number.

198521 is a deficient number, since it is larger than the sum of its proper divisors (3031).

198521 is an equidigital number, since it uses as much as digits as its factorization.

198521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3030.

The product of its digits is 720, while the sum is 26.

The square root of 198521 is about 445.5569548329. The cubic root of 198521 is about 58.3358438829.

The spelling of 198521 in words is "one hundred ninety-eight thousand, five hundred twenty-one".