21211102021 has 16 divisors (see below), whose sum is σ = 22858329600. Its totient is φ = 19633998208.

The previous prime is 21211102013. The next prime is 21211102027. The reversal of 21211102021 is 12020111212.

It is not a de Polignac number, because 21211102021 - 2³ = 21211102013 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21211101992 and 21211102010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21211102027) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14026 + ... + 206443.

It is an arithmetic number, because the mean of its divisors is an integer number (1428645600).

Almost surely, 2^21211102021 is an apocalyptic number.

It is an amenable number.

21211102021 is a deficient number, since it is larger than the sum of its proper divisors (1647227579).

21211102021 is a wasteful number, since it uses less digits than its factorization.

21211102021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 220628.

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

Adding to 21211102021 its reverse (12020111212), we get a palindrome (33231213233).

The spelling of 21211102021 in words is "twenty-one billion, two hundred eleven million, one hundred two thousand, twenty-one".