21101021212 has 12 divisors (see below), whose sum is σ = 37192448440. Its totient is φ = 10474607376.

The previous prime is 21101021203. The next prime is 21101021243. The reversal of 21101021212 is 21212010112.

It is a junction number, because it is equal to n+sod(n) for n = 21101021192 and 21101021201.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 18975183 + ... + 18976294.

Almost surely, 2^21101021212 is an apocalyptic number.

It is an amenable number.

21101021212 is a deficient number, since it is larger than the sum of its proper divisors (16091427228).

21101021212 is a wasteful number, since it uses less digits than its factorization.

21101021212 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37951620 (or 37951618 counting only the distinct ones).

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 21101021212 its reverse (21212010112), we get a palindrome (42313031324).

The spelling of 21101021212 in words is "twenty-one billion, one hundred one million, twenty-one thousand, two hundred twelve".