21230212 has 12 divisors (see below), whose sum is σ = 39338460. Its totient is φ = 9990656.

The previous prime is 21230203. The next prime is 21230213. The reversal of 21230212 is 21203212.

It can be written as a sum of positive squares in 2 ways, for example, as 18181696 + 3048516 = 4264^2 + 1746^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21230192 and 21230201.

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 3 ways as a sum of consecutive naturals, for example, 156037 + ... + 156172.

It is an arithmetic number, because the mean of its divisors is an integer number (3278205).

Almost surely, 2^21230212 is an apocalyptic number.

It is an amenable number.

21230212 is a deficient number, since it is larger than the sum of its proper divisors (18108248).

21230212 is a wasteful number, since it uses less digits than its factorization.

21230212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 312230 (or 312228 counting only the distinct ones).

The product of its (nonzero) digits is 48, while the sum is 13.

The square root of 21230212 is about 4607.6254188031. The cubic root of 21230212 is about 276.8969106410.

Adding to 21230212 its reverse (21203212), we get a palindrome (42433424).

Subtracting from 21230212 its reverse (21203212), we obtain a cube (27000 = 30³).

The spelling of 21230212 in words is "twenty-one million, two hundred thirty thousand, two hundred twelve".