199672391 has 2 divisors, whose sum is σ = 199672392. Its totient is φ = 199672390.

The previous prime is 199672373. The next prime is 199672397. The reversal of 199672391 is 193276991.

It is a strong prime.

It is an emirp because it is prime and its reverse (193276991) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 199672391 - 2¹⁸ = 199410247 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (199672397) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99836195 + 99836196.

It is an arithmetic number, because the mean of its divisors is an integer number (99836196).

Almost surely, 2^199672391 is an apocalyptic number.

199672391 is a deficient number, since it is larger than the sum of its proper divisors (1).

199672391 is an equidigital number, since it uses as much as digits as its factorization.

199672391 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 183708, while the sum is 47.

The square root of 199672391 is about 14130.5481493111. The cubic root of 199672391 is about 584.4840616258.

The spelling of 199672391 in words is "one hundred ninety-nine million, six hundred seventy-two thousand, three hundred ninety-one".