21021330012 has 12 divisors (see below), whose sum is σ = 49049770056. Its totient is φ = 7007110000.

The previous prime is 21021330007. The next prime is 21021330013. The reversal of 21021330012 is 21003312012.

It is a tau number, because it is divible by the number of its divisors (12).

It is a junction number, because it is equal to n+sod(n) for n = 21021329973 and 21021330000.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021330013) 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, 875888739 + ... + 875888762.

It is an arithmetic number, because the mean of its divisors is an integer number (4087480838).

Almost surely, 2^21021330012 is an apocalyptic number.

It is an amenable number.

21021330012 is an abundant number, since it is smaller than the sum of its proper divisors (28028440044).

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

21021330012 is a wasteful number, since it uses less digits than its factorization.

21021330012 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1751777508 (or 1751777506 counting only the distinct ones).

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 21021330012 its reverse (21003312012), we get a palindrome (42024642024).

The spelling of 21021330012 in words is "twenty-one billion, twenty-one million, three hundred thirty thousand, twelve".