21021230212 has 12 divisors (see below), whose sum is σ = 37684400796. Its totient is φ = 10254258560.

The previous prime is 21021230189. The next prime is 21021230221. The reversal of 21021230212 is 21203212012.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 8525567556 + 12495662656 = 92334^2 + 111784^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 64088953 + ... + 64089280.

It is an arithmetic number, because the mean of its divisors is an integer number (3140366733).

Almost surely, 2^21021230212 is an apocalyptic number.

It is an amenable number.

21021230212 is a deficient number, since it is larger than the sum of its proper divisors (16663170584).

21021230212 is a wasteful number, since it uses less digits than its factorization.

21021230212 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128178278 (or 128178276 counting only the distinct ones).

The product of its (nonzero) digits is 96, while the sum is 16.

Adding to 21021230212 its reverse (21203212012), we get a palindrome (42224442224).

The spelling of 21021230212 in words is "twenty-one billion, twenty-one million, two hundred thirty thousand, two hundred twelve".