191093261 has 2 divisors, whose sum is σ = 191093262. Its totient is φ = 191093260.

The previous prime is 191093239. The next prime is 191093263. The reversal of 191093261 is 162390191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 160909225 + 30184036 = 12685^2 + 5494^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-191093261 is a prime.

It is a super-2 number, since 2×191093261² = 73033268799228242, which contains 22 as substring.

Together with 191093263, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191093263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95546630 + 95546631.

It is an arithmetic number, because the mean of its divisors is an integer number (95546631).

Almost surely, 2^191093261 is an apocalyptic number.

It is an amenable number.

191093261 is a deficient number, since it is larger than the sum of its proper divisors (1).

191093261 is an equidigital number, since it uses as much as digits as its factorization.

191093261 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 191093261 is about 13823.6486138790. The cubic root of 191093261 is about 575.9902392331.

The spelling of 191093261 in words is "one hundred ninety-one million, ninety-three thousand, two hundred sixty-one".