21222110 has 32 divisors (see below), whose sum is σ = 47017152. Its totient is φ = 6716160.

The previous prime is 21222043. The next prime is 21222143. The reversal of 21222110 is 1122212.

It is a happy number.

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21222091 and 21222100.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10751 + ... + 12570.

It is an arithmetic number, because the mean of its divisors is an integer number (1469286).

Almost surely, 2^21222110 is an apocalyptic number.

21222110 is an abundant number, since it is smaller than the sum of its proper divisors (25795042).

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

21222110 is a wasteful number, since it uses less digits than its factorization.

21222110 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23348.

The product of its (nonzero) digits is 16, while the sum is 11.

The square root of 21222110 is about 4606.7461401731. The cubic root of 21222110 is about 276.8616824763.

Adding to 21222110 its reverse (1122212), we get a palindrome (22344322).

It can be divided in two parts, 212 and 22110, that added together give a palindrome (22322).

The spelling of 21222110 in words is "twenty-one million, two hundred twenty-two thousand, one hundred ten".