191379557 has 12 divisors (see below), whose sum is σ = 204038340. Its totient is φ = 179467776.

The previous prime is 191379553. The next prime is 191379563. The reversal of 191379557 is 755973191.

It is a Cunningham number, because it is equal to 13834²+1.

It can be written as a sum of positive squares in 6 ways, for example, as 10719076 + 180660481 = 3274^2 + 13441^2 .

It is not a de Polignac number, because 191379557 - 2² = 191379553 is a prime.

It is a super-2 number, since 2×191379557² = 73252269675032498, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (191379553) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 90569 + ... + 92657.

It is an arithmetic number, because the mean of its divisors is an integer number (17003195).

Almost surely, 2^191379557 is an apocalyptic number.

191379557 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

191379557 is a deficient number, since it is larger than the sum of its proper divisors (12658783).

191379557 is a wasteful number, since it uses less digits than its factorization.

191379557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2440 (or 2423 counting only the distinct ones).

The product of its digits is 297675, while the sum is 47.

The square root of 191379557 is about 13834.0000361428. Note that the first 4 decimals coincide. The cubic root of 191379557 is about 576.2777453025.

The spelling of 191379557 in words is "one hundred ninety-one million, three hundred seventy-nine thousand, five hundred fifty-seven".