198134991 has 20 divisors (see below), whose sum is σ = 298612512. Its totient is φ = 130915008.

The previous prime is 198134987. The next prime is 198135019. The reversal of 198134991 is 199431891.

It is not a de Polignac number, because 198134991 - 2² = 198134987 is a prime.

It is a super-3 number, since 3×198134991³ (a number of 26 digits) contains 333 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (198134491) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1671 + ... + 19976.

Almost surely, 2^198134991 is an apocalyptic number.

198134991 is a deficient number, since it is larger than the sum of its proper divisors (100477521).

198134991 is a wasteful number, since it uses less digits than its factorization.

198134991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21772 (or 21763 counting only the distinct ones).

The product of its digits is 69984, while the sum is 45.

The square root of 198134991 is about 14076.0431585016. The cubic root of 198134991 is about 582.9800947829.

The spelling of 198134991 in words is "one hundred ninety-eight million, one hundred thirty-four thousand, nine hundred ninety-one".