199971379 has 2 divisors, whose sum is σ = 199971380. Its totient is φ = 199971378.

The previous prime is 199971329. The next prime is 199971389. The reversal of 199971379 is 973179991.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 199971379 - 2⁷ = 199971251 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (199971329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 99985689 + 99985690.

It is an arithmetic number, because the mean of its divisors is an integer number (99985690).

Almost surely, 2^199971379 is an apocalyptic number.

199971379 is a deficient number, since it is larger than the sum of its proper divisors (1).

199971379 is an equidigital number, since it uses as much as digits as its factorization.

199971379 is an evil number, because the sum of its binary digits is even.

The product of its digits is 964467, while the sum is 55.

The square root of 199971379 is about 14141.1236823670. The cubic root of 199971379 is about 584.7756502079.

The spelling of 199971379 in words is "one hundred ninety-nine million, nine hundred seventy-one thousand, three hundred seventy-nine".