21230210 has 32 divisors (see below), whose sum is σ = 39925872. Its totient is φ = 8120320.

The previous prime is 21230203. The next prime is 21230213. The reversal of 21230210 is 1203212.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 11162281 + 10067929 = 3341^2 + 3173^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21230191 and 21230200.

It is not an unprimeable number, because it can be changed into a prime (21230213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21242 + ... + 22218.

Almost surely, 2^21230210 is an apocalyptic number.

21230210 is a deficient number, since it is larger than the sum of its proper divisors (18695662).

21230210 is a wasteful number, since it uses less digits than its factorization.

21230210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1078.

The product of its (nonzero) digits is 24, while the sum is 11.

The square root of 21230210 is about 4607.6252017715. The cubic root of 21230210 is about 276.8969019459.

Adding to 21230210 its reverse (1203212), we get a palindrome (22433422).

The spelling of 21230210 in words is "twenty-one million, two hundred thirty thousand, two hundred ten".