191517493 has 2 divisors, whose sum is σ = 191517494. Its totient is φ = 191517492.

The previous prime is 191517467. The next prime is 191517497. The reversal of 191517493 is 394715191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 108014449 + 83503044 = 10393^2 + 9138^2 .

It is a cyclic number.

It is not a de Polignac number, because 191517493 - 2⁹ = 191516981 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191517497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95758746 + 95758747.

It is an arithmetic number, because the mean of its divisors is an integer number (95758747).

Almost surely, 2^191517493 is an apocalyptic number.

It is an amenable number.

191517493 is a deficient number, since it is larger than the sum of its proper divisors (1).

191517493 is an equidigital number, since it uses as much as digits as its factorization.

191517493 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 34020, while the sum is 40.

The square root of 191517493 is about 13838.9845364463. The cubic root of 191517493 is about 576.4161619629.

The spelling of 191517493 in words is "one hundred ninety-one million, five hundred seventeen thousand, four hundred ninety-three".