199899431 has 2 divisors, whose sum is σ = 199899432. Its totient is φ = 199899430.

The previous prime is 199899421. The next prime is 199899449. The reversal of 199899431 is 134998991.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199899431 is a prime.

It is a super-2 number, since 2×199899431² = 79919565028247522, which contains 22 as substring.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199899421) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99949715 + 99949716.

It is an arithmetic number, because the mean of its divisors is an integer number (99949716).

Almost surely, 2^199899431 is an apocalyptic number.

199899431 is a deficient number, since it is larger than the sum of its proper divisors (1).

199899431 is an equidigital number, since it uses as much as digits as its factorization.

199899431 is an evil number, because the sum of its binary digits is even.

The product of its digits is 629856, while the sum is 53.

The square root of 199899431 is about 14138.5795255393. The cubic root of 199899431 is about 584.7055093614.

The spelling of 199899431 in words is "one hundred ninety-nine million, eight hundred ninety-nine thousand, four hundred thirty-one".