23020991 has 4 divisors (see below), whose sum is σ = 26309712. Its totient is φ = 19732272.

The previous prime is 23020961. The next prime is 23020997. The reversal of 23020991 is 19902032.

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

It is not a de Polignac number, because 23020991 - 2⁶ = 23020927 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 23020991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (23020997) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1644350 + ... + 1644363.

It is an arithmetic number, because the mean of its divisors is an integer number (6577428).

Almost surely, 2^23020991 is an apocalyptic number.

23020991 is a deficient number, since it is larger than the sum of its proper divisors (3288721).

23020991 is an equidigital number, since it uses as much as digits as its factorization.

23020991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3288720.

The product of its (nonzero) digits is 972, while the sum is 26.

The square root of 23020991 is about 4798.0194872468. The cubic root of 23020991 is about 284.4731870584.

The spelling of 23020991 in words is "twenty-three million, twenty thousand, nine hundred ninety-one".