21221012000 has 48 divisors (see below), whose sum is σ = 52140036312. Its totient is φ = 8488403200.

The previous prime is 21221011961. The next prime is 21221012063. The reversal of 21221012000 is 21012212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 14015718544 + 7205293456 = 118388^2 + 84884^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2648627 + ... + 2656626.

Almost surely, 2^21221012000 is an apocalyptic number.

21221012000 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21221012000 is an abundant number, since it is smaller than the sum of its proper divisors (30919024312).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21221012000 is an equidigital number, since it uses as much as digits as its factorization.

21221012000 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5305278 (or 5305260 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 11.

Adding to 21221012000 its reverse (21012212), we get a palindrome (21242024212).

The spelling of 21221012000 in words is "twenty-one billion, two hundred twenty-one million, twelve thousand".