194259991 has 2 divisors, whose sum is σ = 194259992. Its totient is φ = 194259990.

The previous prime is 194259979. The next prime is 194259997. The reversal of 194259991 is 199952491.

It is a strong prime.

It is an emirp because it is prime and its reverse (199952491) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 194259991 - 2²⁷ = 60042263 is a 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 (194259997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97129995 + 97129996.

It is an arithmetic number, because the mean of its divisors is an integer number (97129996).

Almost surely, 2^194259991 is an apocalyptic number.

194259991 is a deficient number, since it is larger than the sum of its proper divisors (1).

194259991 is an equidigital number, since it uses as much as digits as its factorization.

194259991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 262440, while the sum is 49.

The square root of 194259991 is about 13937.7182852862. The cubic root of 194259991 is about 579.1545261664.

The spelling of 194259991 in words is "one hundred ninety-four million, two hundred fifty-nine thousand, nine hundred ninety-one".