21223013212 has 12 divisors (see below), whose sum is σ = 37141297200. Its totient is φ = 10611214016.

The previous prime is 21223013191. The next prime is 21223013219. The reversal of 21223013212 is 21231032212.

It is a self number, because there is not a number n which added to its sum of digits gives 21223013212.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223013219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 225873 + ... + 305719.

It is an arithmetic number, because the mean of its divisors is an integer number (3095108100).

Almost surely, 2^21223013212 is an apocalyptic number.

It is an amenable number.

21223013212 is a deficient number, since it is larger than the sum of its proper divisors (15918283988).

21223013212 is a wasteful number, since it uses less digits than its factorization.

21223013212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 146300 (or 146298 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

Adding to 21223013212 its reverse (21231032212), we get a palindrome (42454045424).

The spelling of 21223013212 in words is "twenty-one billion, two hundred twenty-three million, thirteen thousand, two hundred twelve".