21422216 has 16 divisors (see below), whose sum is σ = 40219740. Its totient is φ = 10696960.

The previous prime is 21422143. The next prime is 21422221. The reversal of 21422216 is 61222412.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 18957316 + 2464900 = 4354^2 + 1570^2 .

It is a super-2 number, since 2×21422216² = 917822676701312, which contains 22 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7556 + ... + 9996.

Almost surely, 2^21422216 is an apocalyptic number.

It is an amenable number.

21422216 is a deficient number, since it is larger than the sum of its proper divisors (18797524).

21422216 is a wasteful number, since it uses less digits than its factorization.

21422216 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3544 (or 3540 counting only the distinct ones).

The product of its digits is 384, while the sum is 20.

The square root of 21422216 is about 4628.4139832128. The cubic root of 21422216 is about 277.7291497928.

Adding to 21422216 its reverse (61222412), we get a palindrome (82644628).

The spelling of 21422216 in words is "twenty-one million, four hundred twenty-two thousand, two hundred sixteen".