21622215 has 16 divisors (see below), whose sum is σ = 36631008. Its totient is φ = 10853376.

The previous prime is 21622213. The next prime is 21622219. The reversal of 21622215 is 51222612.

It is a happy number.

It is not a de Polignac number, because 21622215 - 2¹ = 21622213 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21622191 and 21622200.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21622213) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 42142 + ... + 42651.

It is an arithmetic number, because the mean of its divisors is an integer number (2289438).

Almost surely, 2^21622215 is an apocalyptic number.

21622215 is a deficient number, since it is larger than the sum of its proper divisors (15008793).

21622215 is a wasteful number, since it uses less digits than its factorization.

21622215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84818.

The product of its digits is 480, while the sum is 21.

The square root of 21622215 is about 4649.9693547377. The cubic root of 21622215 is about 278.5907722080.

Adding to 21622215 its reverse (51222612), we get a palindrome (72844827).

The spelling of 21622215 in words is "twenty-one million, six hundred twenty-two thousand, two hundred fifteen".