21211012 has 12 divisors (see below), whose sum is σ = 37307200. Its totient is φ = 10551816.

The previous prime is 21211009. The next prime is 21211013. The reversal of 21211012 is 21011212.

It is a self number, because there is not a number n which added to its sum of digits gives 21211012.

It is not an unprimeable number, because it can be changed into a prime (21211013) 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, 12528 + ... + 14119.

Almost surely, 2^21211012 is an apocalyptic number.

It is an amenable number.

21211012 is a deficient number, since it is larger than the sum of its proper divisors (16096188).

21211012 is a wasteful number, since it uses less digits than its factorization.

21211012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26850 (or 26848 counting only the distinct ones).

The product of its (nonzero) digits is 8, while the sum is 10.

The square root of 21211012 is about 4605.5414448249. The cubic root of 21211012 is about 276.8134129010.

Adding to 21211012 its reverse (21011212), we get a palindrome (42222224).

The spelling of 21211012 in words is "twenty-one million, two hundred eleven thousand, twelve".