193921109 has 2 divisors, whose sum is σ = 193921110. Its totient is φ = 193921108.

The previous prime is 193921067. The next prime is 193921127. The reversal of 193921109 is 901129391.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 193071025 + 850084 = 13895^2 + 922^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-193921109 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (193921199) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 96960554 + 96960555.

It is an arithmetic number, because the mean of its divisors is an integer number (96960555).

Almost surely, 2^193921109 is an apocalyptic number.

It is an amenable number.

193921109 is a deficient number, since it is larger than the sum of its proper divisors (1).

193921109 is an equidigital number, since it uses as much as digits as its factorization.

193921109 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4374, while the sum is 35.

The square root of 193921109 is about 13925.5559673573. Note that the first 3 decimals coincide. The cubic root of 193921109 is about 578.8175563140.

The spelling of 193921109 in words is "one hundred ninety-three million, nine hundred twenty-one thousand, one hundred nine".