21200012 has 6 divisors (see below), whose sum is σ = 37100028. Its totient is φ = 10600004.

The previous prime is 21199999. The next prime is 21200021. The reversal of 21200012 is 21000212.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2649998 + ... + 2650005.

It is an arithmetic number, because the mean of its divisors is an integer number (6183338).

Almost surely, 2^21200012 is an apocalyptic number.

It is an amenable number.

21200012 is a deficient number, since it is larger than the sum of its proper divisors (15900016).

21200012 is a wasteful number, since it uses less digits than its factorization.

21200012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5300007 (or 5300005 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 8.

The square root of 21200012 is about 4604.3470764051. The cubic root of 21200012 is about 276.7655529488.

Adding to 21200012 its reverse (21000212), we get a palindrome (42200224).

The spelling of 21200012 in words is "twenty-one million, two hundred thousand, twelve".