191838971 has 2 divisors, whose sum is σ = 191838972. Its totient is φ = 191838970.

The previous prime is 191838923. The next prime is 191838989. The reversal of 191838971 is 179838191.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191838971 is a prime.

It is not a weakly prime, because it can be changed into another prime (191838271) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95919485 + 95919486.

It is an arithmetic number, because the mean of its divisors is an integer number (95919486).

Almost surely, 2^191838971 is an apocalyptic number.

191838971 is a deficient number, since it is larger than the sum of its proper divisors (1).

191838971 is an equidigital number, since it uses as much as digits as its factorization.

191838971 is an evil number, because the sum of its binary digits is even.

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

The square root of 191838971 is about 13850.5946081748. The cubic root of 191838971 is about 576.7385024539.

The spelling of 191838971 in words is "one hundred ninety-one million, eight hundred thirty-eight thousand, nine hundred seventy-one".