21202111021 has 32 divisors (see below), whose sum is σ = 26504029440. Its totient is φ = 16513196544.

The previous prime is 21202110977. The next prime is 21202111031. The reversal of 21202111021 is 12011120212.

It is not a de Polignac number, because 21202111021 - 2⁷ = 21202110893 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a junction number, because it is equal to n+sod(n) for n = 21202110992 and 21202111010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202111031) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3737175 + ... + 3742843.

It is an arithmetic number, because the mean of its divisors is an integer number (828250920).

Almost surely, 2^21202111021 is an apocalyptic number.

It is an amenable number.

21202111021 is a deficient number, since it is larger than the sum of its proper divisors (5301918419).

21202111021 is a wasteful number, since it uses less digits than its factorization.

21202111021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6325.

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

Adding to 21202111021 its reverse (12011120212), we get a palindrome (33213231233).

The spelling of 21202111021 in words is "twenty-one billion, two hundred two million, one hundred eleven thousand, twenty-one".