193991939 has 2 divisors, whose sum is σ = 193991940. Its totient is φ = 193991938.

The previous prime is 193991921. The next prime is 193991969. The reversal of 193991939 is 939199391.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-193991939 is a prime.

It is not a weakly prime, because it can be changed into another prime (193991969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 96995969 + 96995970.

It is an arithmetic number, because the mean of its divisors is an integer number (96995970).

Almost surely, 2^193991939 is an apocalyptic number.

193991939 is a deficient number, since it is larger than the sum of its proper divisors (1).

193991939 is an equidigital number, since it uses as much as digits as its factorization.

193991939 is an evil number, because the sum of its binary digits is even.

The product of its digits is 531441, while the sum is 53.

The square root of 193991939 is about 13928.0989011423. The cubic root of 193991939 is about 578.8880190867. Note that the first 3 decimals are identical.

The spelling of 193991939 in words is "one hundred ninety-three million, nine hundred ninety-one thousand, nine hundred thirty-nine".