161391199 has 2 divisors, whose sum is σ = 161391200. Its totient is φ = 161391198.

The previous prime is 161391179. The next prime is 161391227. The reversal of 161391199 is 991193161.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 161391199 - 2⁹ = 161390687 is a prime.

It is a super-2 number, since 2×161391199² = 52094238229315202, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (161391179) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 80695599 + 80695600.

It is an arithmetic number, because the mean of its divisors is an integer number (80695600).

Almost surely, 2^161391199 is an apocalyptic number.

161391199 is a deficient number, since it is larger than the sum of its proper divisors (1).

161391199 is an equidigital number, since it uses as much as digits as its factorization.

161391199 is an evil number, because the sum of its binary digits is even.

The product of its digits is 13122, while the sum is 40.

The square root of 161391199 is about 12703.9835878357. The cubic root of 161391199 is about 544.4524411046.

The spelling of 161391199 in words is "one hundred sixty-one million, three hundred ninety-one thousand, one hundred ninety-nine".