21221200012 has 24 divisors (see below), whose sum is σ = 37293367104. Its totient is φ = 10566034512.

The previous prime is 21221199973. The next prime is 21221200027. The reversal of 21221200012 is 21000212212.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21221199965 and 21221200001.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1082643 + ... + 1102069.

It is an arithmetic number, because the mean of its divisors is an integer number (1553890296).

Almost surely, 2^21221200012 is an apocalyptic number.

It is an amenable number.

21221200012 is a deficient number, since it is larger than the sum of its proper divisors (16072167092).

21221200012 is a wasteful number, since it uses less digits than its factorization.

21221200012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20565 (or 20563 counting only the distinct ones).

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 21221200012 its reverse (21000212212), we get a palindrome (42221412224).

The spelling of 21221200012 in words is "twenty-one billion, two hundred twenty-one million, two hundred thousand, twelve".