21233010221 has 6 divisors (see below), whose sum is σ = 21343633290. Its totient is φ = 21122957568.

The previous prime is 21233010209. The next prime is 21233010223. The reversal of 21233010221 is 12201033212.

It can be written as a sum of positive squares in 3 ways, for example, as 5096389321 + 16136620900 = 71389^2 + 127030^2 .

It is a de Polignac number, because none of the positive numbers 2^k-21233010221 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21233010221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21233010223) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 247766 + ... + 322263.

It is an arithmetic number, because the mean of its divisors is an integer number (3557272215).

Almost surely, 2^21233010221 is an apocalyptic number.

It is an amenable number.

21233010221 is a deficient number, since it is larger than the sum of its proper divisors (110623069).

21233010221 is an frugal number, since it uses more digits than its factorization.

21233010221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 570415 (or 570222 counting only the distinct ones).

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 21233010221 its reverse (12201033212), we get a palindrome (33434043433).

The spelling of 21233010221 in words is "twenty-one billion, two hundred thirty-three million, ten thousand, two hundred twenty-one".