21033310021 has 8 divisors (see below), whose sum is σ = 21385319000. Its totient is φ = 20681533440.

The previous prime is 21033310019. The next prime is 21033310057. The reversal of 21033310021 is 12001333012.

It can be written as a sum of positive squares in 4 ways, for example, as 502432225 + 20530877796 = 22415^2 + 143286^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21033310021 - 2¹ = 21033310019 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21033309977 and 21033310004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21033310091) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 129445 + ... + 242533.

It is an arithmetic number, because the mean of its divisors is an integer number (2673164875).

Almost surely, 2^21033310021 is an apocalyptic number.

It is an amenable number.

21033310021 is a deficient number, since it is larger than the sum of its proper divisors (352008979).

21033310021 is a wasteful number, since it uses less digits than its factorization.

21033310021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116199.

The product of its (nonzero) digits is 108, while the sum is 16.

Adding to 21033310021 its reverse (12001333012), we get a palindrome (33034643033).

The spelling of 21033310021 in words is "twenty-one billion, thirty-three million, three hundred ten thousand, twenty-one".