21202033221 has 24 divisors (see below), whose sum is σ = 30949609080. Its totient is φ = 13985136000.

The previous prime is 21202033169. The next prime is 21202033231. The reversal of 21202033221 is 12233020212.

It can be written as a sum of positive squares in 4 ways, for example, as 9122924196 + 12079109025 = 95514^2 + 109905^2 .

It is not a de Polignac number, because 21202033221 - 2¹¹ = 21202031173 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21202033194 and 21202033203.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21202033231) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1466295 + ... + 1480683.

It is an arithmetic number, because the mean of its divisors is an integer number (1289567045).

Almost surely, 2^21202033221 is an apocalyptic number.

It is an amenable number.

21202033221 is a deficient number, since it is larger than the sum of its proper divisors (9747575859).

21202033221 is a wasteful number, since it uses less digits than its factorization.

21202033221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16117 (or 16114 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

Adding to 21202033221 its reverse (12233020212), we get a palindrome (33435053433).

The spelling of 21202033221 in words is "twenty-one billion, two hundred two million, thirty-three thousand, two hundred twenty-one".