198551 has 4 divisors (see below), whose sum is σ = 199704. Its totient is φ = 197400.

The previous prime is 198533. The next prime is 198553. The reversal of 198551 is 155891.

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 198551 - 2¹⁴ = 182167 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 (198553) 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, 260 + ... + 681.

It is an arithmetic number, because the mean of its divisors is an integer number (49926).

2¹⁹⁸⁵⁵¹ is an apocalyptic number.

198551 is a deficient number, since it is larger than the sum of its proper divisors (1153).

198551 is an equidigital number, since it uses as much as digits as its factorization.

198551 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1152.

The product of its digits is 1800, while the sum is 29.

The square root of 198551 is about 445.5906192908. The cubic root of 198551 is about 58.3387822574.

The spelling of 198551 in words is "one hundred ninety-eight thousand, five hundred fifty-one".