191968739 has 2 divisors, whose sum is σ = 191968740. Its totient is φ = 191968738.

The previous prime is 191968717. The next prime is 191968753. The reversal of 191968739 is 937869191.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191968739 is a prime.

It is not a weakly prime, because it can be changed into another prime (191968759) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95984369 + 95984370.

It is an arithmetic number, because the mean of its divisors is an integer number (95984370).

Almost surely, 2^191968739 is an apocalyptic number.

191968739 is a deficient number, since it is larger than the sum of its proper divisors (1).

191968739 is an equidigital number, since it uses as much as digits as its factorization.

191968739 is an evil number, because the sum of its binary digits is even.

The product of its digits is 734832, while the sum is 53.

The square root of 191968739 is about 13855.2783804585. The cubic root of 191968739 is about 576.8685165876.

The spelling of 191968739 in words is "one hundred ninety-one million, nine hundred sixty-eight thousand, seven hundred thirty-nine".