21022222 has 16 divisors (see below), whose sum is σ = 34040160. Its totient is φ = 9679392.

The previous prime is 21022219. The next prime is 21022223. The reversal of 21022222 is 22222012.

It is a Harshad number since it is a multiple of its sum of digits (13).

21022222 is a modest number, since divided by 2222 gives 2102 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21022223) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15279 + ... + 16597.

It is an arithmetic number, because the mean of its divisors is an integer number (2127510).

Almost surely, 2^21022222 is an apocalyptic number.

21022222 is a deficient number, since it is larger than the sum of its proper divisors (13017938).

21022222 is a wasteful number, since it uses less digits than its factorization.

21022222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1947.

The product of its (nonzero) digits is 64, while the sum is 13.

The square root of 21022222 is about 4584.9996728462. Note that the first 3 decimals coincide. The cubic root of 21022222 is about 275.9896989084.

Adding to 21022222 its reverse (22222012), we get a palindrome (43244234).

The spelling of 21022222 in words is "twenty-one million, twenty-two thousand, two hundred twenty-two".