199912931 has 2 divisors, whose sum is σ = 199912932. Its totient is φ = 199912930.

The previous prime is 199912913. The next prime is 199912969. The reversal of 199912931 is 139219991.

Together with previous prime (199912913) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-199912931 is a prime.

It is a super-2 number, since 2×199912931² = 79930359962021522, which contains 22 as substring.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (199912901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99956465 + 99956466.

It is an arithmetic number, because the mean of its divisors is an integer number (99956466).

Almost surely, 2^199912931 is an apocalyptic number.

199912931 is a deficient number, since it is larger than the sum of its proper divisors (1).

199912931 is an equidigital number, since it uses as much as digits as its factorization.

199912931 is an evil number, because the sum of its binary digits is even.

The product of its digits is 39366, while the sum is 44.

The square root of 199912931 is about 14139.0569346049. The cubic root of 199912931 is about 584.7186715578.

It can be divided in two parts, 19991 and 2931, that added together give a palindrome (22922).

The spelling of 199912931 in words is "one hundred ninety-nine million, nine hundred twelve thousand, nine hundred thirty-one".