194991919 has 2 divisors, whose sum is σ = 194991920. Its totient is φ = 194991918.

The previous prime is 194991883. The next prime is 194991931. The reversal of 194991919 is 919199491.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 194991919 - 2¹¹ = 194989871 is a prime.

It is a super-2 number, since 2×194991919² = 76043696950605122, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (194991949) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97495959 + 97495960.

It is an arithmetic number, because the mean of its divisors is an integer number (97495960).

Almost surely, 2^194991919 is an apocalyptic number.

194991919 is a deficient number, since it is larger than the sum of its proper divisors (1).

194991919 is an equidigital number, since it uses as much as digits as its factorization.

194991919 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 236196, while the sum is 52.

The square root of 194991919 is about 13963.9506945563. The cubic root of 194991919 is about 579.8809892559.

The spelling of 194991919 in words is "one hundred ninety-four million, nine hundred ninety-one thousand, nine hundred nineteen".