194209891 has 2 divisors, whose sum is σ = 194209892. Its totient is φ = 194209890.

The previous prime is 194209879. The next prime is 194209901. The reversal of 194209891 is 198902491.

It is a happy number.

194209891 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 194209891 - 2¹¹ = 194207843 is a prime.

It is not a weakly prime, because it can be changed into another prime (194209831) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 97104945 + 97104946.

It is an arithmetic number, because the mean of its divisors is an integer number (97104946).

Almost surely, 2^194209891 is an apocalyptic number.

194209891 is a deficient number, since it is larger than the sum of its proper divisors (1).

194209891 is an equidigital number, since it uses as much as digits as its factorization.

194209891 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 46656, while the sum is 43.

The square root of 194209891 is about 13935.9208881222. The cubic root of 194209891 is about 579.1047335554.

The spelling of 194209891 in words is "one hundred ninety-four million, two hundred nine thousand, eight hundred ninety-one".