198657 has 6 divisors (see below), whose sum is σ = 286962. Its totient is φ = 132432.

The previous prime is 198647. The next prime is 198659. The reversal of 198657 is 756891.

198657 is nontrivially palindromic in base 12.

It can be written as a sum of positive squares in only one way, i.e., 197136 + 1521 = 444^2 + 39^2 .

It is not a de Polignac number, because 198657 - 2⁴ = 198641 is a prime.

It is not an unprimeable number, because it can be changed into a prime (198659) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 11028 + ... + 11045.

It is an arithmetic number, because the mean of its divisors is an integer number (47827).

It is a Proth number, since it is equal to 97 ⋅ 2¹¹ + 1 and 97 < 2¹¹.

2¹⁹⁸⁶⁵⁷ is an apocalyptic number.

It is an amenable number.

198657 is a deficient number, since it is larger than the sum of its proper divisors (88305).

198657 is a wasteful number, since it uses less digits than its factorization.

198657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22079 (or 22076 counting only the distinct ones).

The product of its digits is 15120, while the sum is 36.

The square root of 198657 is about 445.7095466781. The cubic root of 198657 is about 58.3491621444.

The spelling of 198657 in words is "one hundred ninety-eight thousand, six hundred fifty-seven".