21210222 has 16 divisors (see below), whose sum is σ = 46276992. Its totient is φ = 6427320.

The previous prime is 21210221. The next prime is 21210227. The reversal of 21210222 is 22201212.

It is a junction number, because it is equal to n+sod(n) for n = 21210198 and 21210207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21210221) 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, 160618 + ... + 160749.

It is an arithmetic number, because the mean of its divisors is an integer number (2892312).

Almost surely, 2^21210222 is an apocalyptic number.

21210222 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21210222 is an abundant number, since it is smaller than the sum of its proper divisors (25066770).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21210222 is a wasteful number, since it uses less digits than its factorization.

21210222 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 321383.

The product of its (nonzero) digits is 32, while the sum is 12.

The square root of 21210222 is about 4605.4556777804. The cubic root of 21210222 is about 276.8099762378.

Adding to 21210222 its reverse (22201212), we get a palindrome (43411434).

The spelling of 21210222 in words is "twenty-one million, two hundred ten thousand, two hundred twenty-two".