20011223 has 4 divisors (see below), whose sum is σ = 20020248. Its totient is φ = 20002200.

The previous prime is 20011177. The next prime is 20011249. The reversal of 20011223 is 32211002.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 32211002 = 2 ⋅16105501.

It is a cyclic number.

It is not a de Polignac number, because 20011223 - 2⁸ = 20010967 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 (20011273) 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 3 ways as a sum of consecutive naturals, for example, 1373 + ... + 6473.

It is an arithmetic number, because the mean of its divisors is an integer number (5005062).

Almost surely, 2^20011223 is an apocalyptic number.

20011223 is a deficient number, since it is larger than the sum of its proper divisors (9025).

20011223 is an equidigital number, since it uses as much as digits as its factorization.

20011223 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9024.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 20011223 is about 4473.3905485660. The cubic root of 20011223 is about 271.4925253468.

Adding to 20011223 its reverse (32211002), we get a palindrome (52222225).

The spelling of 20011223 in words is "twenty million, eleven thousand, two hundred twenty-three".