199939631 has 2 divisors, whose sum is σ = 199939632. Its totient is φ = 199939630.

The previous prime is 199939589. The next prime is 199939643. The reversal of 199939631 is 136939991.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199939631 is a prime.

It is a super-2 number, since 2×199939631² = 79951712088832322, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 199939631.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199939651) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99969815 + 99969816.

It is an arithmetic number, because the mean of its divisors is an integer number (99969816).

Almost surely, 2^199939631 is an apocalyptic number.

199939631 is a deficient number, since it is larger than the sum of its proper divisors (1).

199939631 is an equidigital number, since it uses as much as digits as its factorization.

199939631 is an evil number, because the sum of its binary digits is even.

The product of its digits is 354294, while the sum is 50.

The square root of 199939631 is about 14140.0010961810. The cubic root of 199939631 is about 584.7447017124.

The spelling of 199939631 in words is "one hundred ninety-nine million, nine hundred thirty-nine thousand, six hundred thirty-one".