20231191 has 4 divisors (see below), whose sum is σ = 21110832. Its totient is φ = 19351552.

The previous prime is 20231179. The next prime is 20231203. The reversal of 20231191 is 19113202.

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 (20231179) and next prime (20231203).

It is a cyclic number.

It is not a de Polignac number, because 20231191 - 2⁷ = 20231063 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20231161) 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, 439786 + ... + 439831.

It is an arithmetic number, because the mean of its divisors is an integer number (5277708).

Almost surely, 2^20231191 is an apocalyptic number.

20231191 is a deficient number, since it is larger than the sum of its proper divisors (879641).

20231191 is an equidigital number, since it uses as much as digits as its factorization.

20231191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 879640.

The product of its (nonzero) digits is 108, while the sum is 19.

The square root of 20231191 is about 4497.9096255928. The cubic root of 20231191 is about 272.4836721132.

Adding to 20231191 its reverse (19113202), we get a palindrome (39344393).

The spelling of 20231191 in words is "twenty million, two hundred thirty-one thousand, one hundred ninety-one".