191881793 has 2 divisors, whose sum is σ = 191881794. Its totient is φ = 191881792.

The previous prime is 191881751. The next prime is 191881799. The reversal of 191881793 is 397188191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 112190464 + 79691329 = 10592^2 + 8927^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191881793 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (191881799) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95940896 + 95940897.

It is an arithmetic number, because the mean of its divisors is an integer number (95940897).

Almost surely, 2^191881793 is an apocalyptic number.

It is an amenable number.

191881793 is a deficient number, since it is larger than the sum of its proper divisors (1).

191881793 is an equidigital number, since it uses as much as digits as its factorization.

191881793 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 108864, while the sum is 47.

The square root of 191881793 is about 13852.1403761296. The cubic root of 191881793 is about 576.7814121551.

The spelling of 191881793 in words is "one hundred ninety-one million, eight hundred eighty-one thousand, seven hundred ninety-three".