191116531 has 2 divisors, whose sum is σ = 191116532. Its totient is φ = 191116530.

The previous prime is 191116529. The next prime is 191116579. The reversal of 191116531 is 135611191.

It is a weak prime.

It is an emirp because it is prime and its reverse (135611191) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 191116531 - 2¹ = 191116529 is a prime.

It is a super-2 number, since 2×191116531² = 73051056842947922, which contains 22 as substring.

Together with 191116529, it forms a pair of twin primes.

It is a self number, because there is not a number n which added to its sum of digits gives 191116531.

It is not a weakly prime, because it can be changed into another prime (191116511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 95558265 + 95558266.

It is an arithmetic number, because the mean of its divisors is an integer number (95558266).

Almost surely, 2^191116531 is an apocalyptic number.

191116531 is the 6183-rd centered decagonal number.

191116531 is a deficient number, since it is larger than the sum of its proper divisors (1).

191116531 is an equidigital number, since it uses as much as digits as its factorization.

191116531 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 810, while the sum is 28.

The square root of 191116531 is about 13824.4902618505. The cubic root of 191116531 is about 576.0136183042.

The spelling of 191116531 in words is "one hundred ninety-one million, one hundred sixteen thousand, five hundred thirty-one".