20311223 has 4 divisors (see below), whose sum is σ = 21011640. Its totient is φ = 19610808.

The previous prime is 20311211. The next prime is 20311273. The reversal of 20311223 is 32211302.

It is a happy number.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20311223 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20311198 and 20311207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20311273) 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, 350165 + ... + 350222.

It is an arithmetic number, because the mean of its divisors is an integer number (5252910).

Almost surely, 2^20311223 is an apocalyptic number.

20311223 is a deficient number, since it is larger than the sum of its proper divisors (700417).

20311223 is an equidigital number, since it uses as much as digits as its factorization.

20311223 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 700416.

The product of its (nonzero) digits is 72, while the sum is 14.

The square root of 20311223 is about 4506.7974216732. The cubic root of 20311223 is about 272.8425028661.

Adding to 20311223 its reverse (32211302), we get a palindrome (52522525).

The spelling of 20311223 in words is "twenty million, three hundred eleven thousand, two hundred twenty-three".