191042557 has 2 divisors, whose sum is σ = 191042558. Its totient is φ = 191042556.

The previous prime is 191042497. The next prime is 191042561. The reversal of 191042557 is 755240191.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 190605636 + 436921 = 13806^2 + 661^2 .

It is a cyclic number.

It is not a de Polignac number, because 191042557 - 2¹⁵ = 191009789 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191042857) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95521278 + 95521279.

It is an arithmetic number, because the mean of its divisors is an integer number (95521279).

Almost surely, 2^191042557 is an apocalyptic number.

It is an amenable number.

191042557 is a deficient number, since it is larger than the sum of its proper divisors (1).

191042557 is an equidigital number, since it uses as much as digits as its factorization.

191042557 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12600, while the sum is 34.

The square root of 191042557 is about 13821.8145335553. The cubic root of 191042557 is about 575.9392909991.

The spelling of 191042557 in words is "one hundred ninety-one million, forty-two thousand, five hundred fifty-seven".