198649 has 4 divisors (see below), whose sum is σ = 216720. Its totient is φ = 180580.

The previous prime is 198647. The next prime is 198659. The reversal of 198649 is 946891.

198649 = 61² + 62² + ... + 93².

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 not a de Polignac number, because 198649 - 2¹ = 198647 is a prime.

It is a super-2 number, since 2×198649² = 78922850402, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (198641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9019 + ... + 9040.

It is an arithmetic number, because the mean of its divisors is an integer number (54180).

2¹⁹⁸⁶⁴⁹ is an apocalyptic number.

It is an amenable number.

198649 is a deficient number, since it is larger than the sum of its proper divisors (18071).

198649 is a wasteful number, since it uses less digits than its factorization.

198649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18070.

The product of its digits is 15552, while the sum is 37.

The square root of 198649 is about 445.7005721334. The cubic root of 198649 is about 58.3483788855.

It can be divided in two parts, 19 and 8649, that added together give a palindrome (8668).

The spelling of 198649 in words is "one hundred ninety-eight thousand, six hundred forty-nine".