21223219 has 2 divisors, whose sum is σ = 21223220. Its totient is φ = 21223218.

The previous prime is 21223193. The next prime is 21223261. The reversal of 21223219 is 91232212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21223219 - 2⁵ = 21223187 is a prime.

It is a super-2 number, since 2×21223219² = 900850049443922, which contains 22 as substring.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21223219.

It is not a weakly prime, because it can be changed into another prime (21223519) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10611609 + 10611610.

It is an arithmetic number, because the mean of its divisors is an integer number (10611610).

Almost surely, 2^21223219 is an apocalyptic number.

21223219 is a deficient number, since it is larger than the sum of its proper divisors (1).

21223219 is an equidigital number, since it uses as much as digits as its factorization.

21223219 is an evil number, because the sum of its binary digits is even.

The product of its digits is 432, while the sum is 22.

The square root of 21223219 is about 4606.8665055545. The cubic root of 21223219 is about 276.8665050294.

It can be divided in two parts, 2 and 1223219, that added together give a palindrome (1223221).

The spelling of 21223219 in words is "twenty-one million, two hundred twenty-three thousand, two hundred nineteen".