21112210 has 32 divisors (see below), whose sum is σ = 43845120. Its totient is φ = 7169472.

The previous prime is 21112207. The next prime is 21112241. The reversal of 21112210 is 1221112.

It is a super-2 number, since 2×21112210² = 891450822168200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (10).

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, 6247 + ... + 9013.

It is an arithmetic number, because the mean of its divisors is an integer number (1370160).

Almost surely, 2^21112210 is an apocalyptic number.

21112210 is an abundant number, since it is smaller than the sum of its proper divisors (22732910).

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

21112210 is a wasteful number, since it uses less digits than its factorization.

21112210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2890.

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 21112210 is about 4594.8024984759. The cubic root of 21112210 is about 276.3829400484.

Adding to 21112210 its reverse (1221112), we get a palindrome (22333322).

It can be divided in two parts, 211 and 12210, that added together give a palindrome (12421).

The spelling of 21112210 in words is "twenty-one million, one hundred twelve thousand, two hundred ten".