21022210 has 32 divisors (see below), whose sum is σ = 41513472. Its totient is φ = 7601280.

The previous prime is 21022193. The next prime is 21022213. The reversal of 21022210 is 1222012.

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

It is not an unprimeable number, because it can be changed into a prime (21022213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24102 + ... + 24958.

It is an arithmetic number, because the mean of its divisors is an integer number (1297296).

Almost surely, 2^21022210 is an apocalyptic number.

21022210 is a deficient number, since it is larger than the sum of its proper divisors (20491262).

21022210 is a wasteful number, since it uses less digits than its factorization.

21022210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1098.

The product of its (nonzero) digits is 16, while the sum is 10.

The square root of 21022210 is about 4584.9983642309. The cubic root of 21022210 is about 275.9896463945.

Adding to 21022210 its reverse (1222012), we get a palindrome (22244222).

The spelling of 21022210 in words is "twenty-one million, twenty-two thousand, two hundred ten".