198665431 has 2 divisors, whose sum is σ = 198665432. Its totient is φ = 198665430.

The previous prime is 198665407. The next prime is 198665491. The reversal of 198665431 is 134566891.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 198665431 - 2¹¹ = 198663383 is a prime.

It is a super-2 number, since 2×198665431² = 78935906948831522, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (198665491) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99332715 + 99332716.

It is an arithmetic number, because the mean of its divisors is an integer number (99332716).

Almost surely, 2^198665431 is an apocalyptic number.

198665431 is a deficient number, since it is larger than the sum of its proper divisors (1).

198665431 is an equidigital number, since it uses as much as digits as its factorization.

198665431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 155520, while the sum is 43.

The square root of 198665431 is about 14094.8725074050. The cubic root of 198665431 is about 583.4998757852.

The spelling of 198665431 in words is "one hundred ninety-eight million, six hundred sixty-five thousand, four hundred thirty-one".