21222219 has 16 divisors (see below), whose sum is σ = 28749600. Its totient is φ = 13923840.

The previous prime is 21222211. The next prime is 21222251. The reversal of 21222219 is 91222212.

It is a happy number.

It is not a de Polignac number, because 21222219 - 2³ = 21222211 is a prime.

It is a super-2 number, since 2×21222219² = 900765158567922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21222195 and 21222204.

It is not an unprimeable number, because it can be changed into a prime (21222211) 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 15 ways as a sum of consecutive naturals, for example, 87939 + ... + 88179.

It is an arithmetic number, because the mean of its divisors is an integer number (1796850).

Almost surely, 2^21222219 is an apocalyptic number.

21222219 is a deficient number, since it is larger than the sum of its proper divisors (7527381).

21222219 is a wasteful number, since it uses less digits than its factorization.

21222219 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 590.

The product of its digits is 288, while the sum is 21.

The square root of 21222219 is about 4606.7579706340. The cubic root of 21222219 is about 276.8621564768.

It can be divided in two parts, 2 and 1222219, that added together give a palindrome (1222221).

The spelling of 21222219 in words is "twenty-one million, two hundred twenty-two thousand, two hundred nineteen".