194778719 has 2 divisors, whose sum is σ = 194778720. Its totient is φ = 194778718.

The previous prime is 194778679. The next prime is 194778721. The reversal of 194778719 is 917877491.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 194778719 - 2²⁰ = 193730143 is a prime.

It is a super-2 number, since 2×194778719² = 75877498750561922, which contains 22 as substring.

Together with 194778721, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (194778769) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97389359 + 97389360.

It is an arithmetic number, because the mean of its divisors is an integer number (97389360).

Almost surely, 2^194778719 is an apocalyptic number.

194778719 is a deficient number, since it is larger than the sum of its proper divisors (1).

194778719 is an equidigital number, since it uses as much as digits as its factorization.

194778719 is an evil number, because the sum of its binary digits is even.

The product of its digits is 889056, while the sum is 53.

The square root of 194778719 is about 13956.3146639792. The cubic root of 194778719 is about 579.6695690198.

The spelling of 194778719 in words is "one hundred ninety-four million, seven hundred seventy-eight thousand, seven hundred nineteen".