20440223 has 4 divisors (see below), whose sum is σ = 20699040. Its totient is φ = 20181408.

The previous prime is 20440213. The next prime is 20440249. The reversal of 20440223 is 32204402.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 32204402 = 2 ⋅16102201.

It is a cyclic number.

It is not a de Polignac number, because 20440223 - 2⁴ = 20440207 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 (20440213) 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, 129290 + ... + 129447.

It is an arithmetic number, because the mean of its divisors is an integer number (5174760).

Almost surely, 2^20440223 is an apocalyptic number.

20440223 is a deficient number, since it is larger than the sum of its proper divisors (258817).

20440223 is an equidigital number, since it uses as much as digits as its factorization.

20440223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258816.

The product of its (nonzero) digits is 384, while the sum is 17.

The square root of 20440223 is about 4521.0864844637. The cubic root of 20440223 is about 273.4189072071.

Adding to 20440223 its reverse (32204402), we get a palindrome (52644625).

The spelling of 20440223 in words is "twenty million, four hundred forty thousand, two hundred twenty-three".