191223091 has 4 divisors (see below), whose sum is σ = 191722752. Its totient is φ = 190723432.

The previous prime is 191223079. The next prime is 191223103. The reversal of 191223091 is 190322191.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (191223079) and next prime (191223103).

It is a cyclic number.

It is not a de Polignac number, because 191223091 - 2⁵ = 191223059 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (191223031) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 249256 + ... + 250021.

It is an arithmetic number, because the mean of its divisors is an integer number (47930688).

Almost surely, 2^191223091 is an apocalyptic number.

191223091 is a deficient number, since it is larger than the sum of its proper divisors (499661).

191223091 is an equidigital number, since it uses as much as digits as its factorization.

191223091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 499660.

The product of its (nonzero) digits is 972, while the sum is 28.

The square root of 191223091 is about 13828.3437547669. The cubic root of 191223091 is about 576.1206535366.

The spelling of 191223091 in words is "one hundred ninety-one million, two hundred twenty-three thousand, ninety-one".