191981135 has 8 divisors (see below), whose sum is σ = 235279296. Its totient is φ = 150316960.

The previous prime is 191981117. The next prime is 191981143. The reversal of 191981135 is 531189191.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 191981135 - 2⁸ = 191980879 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 408236 + ... + 408705.

It is an arithmetic number, because the mean of its divisors is an integer number (29409912).

Almost surely, 2^191981135 is an apocalyptic number.

191981135 is a deficient number, since it is larger than the sum of its proper divisors (43298161).

191981135 is an equidigital number, since it uses as much as digits as its factorization.

191981135 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 816993.

The product of its digits is 9720, while the sum is 38.

The square root of 191981135 is about 13855.7257117771. The cubic root of 191981135 is about 576.8809330332.

The spelling of 191981135 in words is "one hundred ninety-one million, nine hundred eighty-one thousand, one hundred thirty-five".