21311020012 has 6 divisors (see below), whose sum is σ = 37294285028. Its totient is φ = 10655510004.

The previous prime is 21311019997. The next prime is 21311020039. The reversal of 21311020012 is 21002011312.

It is a junction number, because it is equal to n+sod(n) for n = 21311019974 and 21311020001.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2663877498 + ... + 2663877505.

Almost surely, 2^21311020012 is an apocalyptic number.

It is an amenable number.

21311020012 is a deficient number, since it is larger than the sum of its proper divisors (15983265016).

21311020012 is a wasteful number, since it uses less digits than its factorization.

21311020012 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5327755007 (or 5327755005 counting only the distinct ones).

The product of its (nonzero) digits is 24, while the sum is 13.

Adding to 21311020012 its reverse (21002011312), we get a palindrome (42313031324).

The spelling of 21311020012 in words is "twenty-one billion, three hundred eleven million, twenty thousand, twelve".