191026861 has 2 divisors, whose sum is σ = 191026862. Its totient is φ = 191026860.

The previous prime is 191026777. The next prime is 191026877. The reversal of 191026861 is 168620191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 179426025 + 11600836 = 13395^2 + 3406^2 .

It is a cyclic number.

It is not a de Polignac number, because 191026861 - 2²⁷ = 56809133 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191026261) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95513430 + 95513431.

It is an arithmetic number, because the mean of its divisors is an integer number (95513431).

Almost surely, 2^191026861 is an apocalyptic number.

It is an amenable number.

191026861 is a deficient number, since it is larger than the sum of its proper divisors (1).

191026861 is an equidigital number, since it uses as much as digits as its factorization.

191026861 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 191026861 is about 13821.2467237945. The cubic root of 191026861 is about 575.9235175665.

The spelling of 191026861 in words is "one hundred ninety-one million, twenty-six thousand, eight hundred sixty-one".