191916971 has 2 divisors, whose sum is σ = 191916972. Its totient is φ = 191916970.

The previous prime is 191916943. The next prime is 191916979. The reversal of 191916971 is 179619191.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 191916971 - 2¹⁴ = 191900587 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (191916979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95958485 + 95958486.

It is an arithmetic number, because the mean of its divisors is an integer number (95958486).

Almost surely, 2^191916971 is an apocalyptic number.

191916971 is a deficient number, since it is larger than the sum of its proper divisors (1).

191916971 is an equidigital number, since it uses as much as digits as its factorization.

191916971 is an evil number, because the sum of its binary digits is even.

The product of its digits is 30618, while the sum is 44.

The square root of 191916971 is about 13853.4100856071. The cubic root of 191916971 is about 576.8166574249.

It can be divided in two parts, 19191 and 6971, that added together give a palindrome (26162).

The spelling of 191916971 in words is "one hundred ninety-one million, nine hundred sixteen thousand, nine hundred seventy-one".