191985559 has 2 divisors, whose sum is σ = 191985560. Its totient is φ = 191985558.

The previous prime is 191985551. The next prime is 191985571. The reversal of 191985559 is 955589191.

It is a weak prime.

It is an emirp because it is prime and its reverse (955589191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 191985559 - 2³ = 191985551 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (191985551) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95992779 + 95992780.

It is an arithmetic number, because the mean of its divisors is an integer number (95992780).

Almost surely, 2^191985559 is an apocalyptic number.

191985559 is a deficient number, since it is larger than the sum of its proper divisors (1).

191985559 is an equidigital number, since it uses as much as digits as its factorization.

191985559 is an evil number, because the sum of its binary digits is even.

The product of its digits is 729000, while the sum is 52.

The square root of 191985559 is about 13855.8853560500. The cubic root of 191985559 is about 576.8853642006.

It can be divided in two parts, 1919 and 85559, that added together give a palindrome (87478).

The spelling of 191985559 in words is "one hundred ninety-one million, nine hundred eighty-five thousand, five hundred fifty-nine".