21222123 has 32 divisors (see below), whose sum is σ = 32417280. Its totient is φ = 12249600.

The previous prime is 21222043. The next prime is 21222143. The reversal of 21222123 is 32122212.

It is a happy number.

It is not a de Polignac number, because 21222123 - 2⁸ = 21221867 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21222143) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52723 + ... + 53123.

It is an arithmetic number, because the mean of its divisors is an integer number (1013040).

Almost surely, 2^21222123 is an apocalyptic number.

21222123 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21222123 is a deficient number, since it is larger than the sum of its proper divisors (11195157).

21222123 is a wasteful number, since it uses less digits than its factorization.

21222123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 499.

The product of its digits is 96, while the sum is 15.

The square root of 21222123 is about 4606.7475511471. The cubic root of 21222123 is about 276.8617390086.

Adding to 21222123 its reverse (32122212), we get a palindrome (53344335).

It can be divided in two parts, 2122212 and 3, that multiplied together give a palindrome (6366636).

The spelling of 21222123 in words is "twenty-one million, two hundred twenty-two thousand, one hundred twenty-three".