191939209091 has 8 divisors (see below), whose sum is σ = 224460470784. Its totient is φ = 160693291080.

The previous prime is 191939209003. The next prime is 191939209097. The reversal of 191939209091 is 190902939191.

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

It is not a de Polignac number, because 191939209091 - 2¹⁴ = 191939192707 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (191939209097) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 318835595 + ... + 318836196.

It is an arithmetic number, because the mean of its divisors is an integer number (28057558848).

Almost surely, 2^191939209091 is an apocalyptic number.

191939209091 is a deficient number, since it is larger than the sum of its proper divisors (32521261693).

191939209091 is an equidigital number, since it uses as much as digits as its factorization.

191939209091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 637671841.

The product of its (nonzero) digits is 354294, while the sum is 53.

The spelling of 191939209091 in words is "one hundred ninety-one billion, nine hundred thirty-nine million, two hundred nine thousand, ninety-one".