191940691 has 8 divisors (see below), whose sum is σ = 198894080. Its totient is φ = 185100552.

The previous prime is 191940689. The next prime is 191940733. The reversal of 191940691 is 196049191.

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

It is not a de Polignac number, because 191940691 - 2¹ = 191940689 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (191940601) 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 7 ways as a sum of consecutive naturals, for example, 24855 + ... + 31648.

It is an arithmetic number, because the mean of its divisors is an integer number (24861760).

Almost surely, 2^191940691 is an apocalyptic number.

191940691 is a deficient number, since it is larger than the sum of its proper divisors (6953389).

191940691 is an equidigital number, since it uses as much as digits as its factorization.

191940691 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56625.

The product of its (nonzero) digits is 17496, while the sum is 40.

The square root of 191940691 is about 13854.2661660587. The cubic root of 191940691 is about 576.8404203529.

The spelling of 191940691 in words is "one hundred ninety-one million, nine hundred forty thousand, six hundred ninety-one".