21333221001 has 12 divisors (see below), whose sum is σ = 32627279412. Its totient is φ = 13385550336.

The previous prime is 21333220991. The next prime is 21333221029. The reversal of 21333221001 is 10012233312.

It can be written as a sum of positive squares in 2 ways, for example, as 19237412601 + 2095808400 = 138699^2 + 45780^2 .

It is not a de Polignac number, because 21333221001 - 2¹⁷ = 21333089929 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21333221101) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 69716256 + ... + 69716561.

It is an arithmetic number, because the mean of its divisors is an integer number (2718939951).

Almost surely, 2^21333221001 is an apocalyptic number.

It is an amenable number.

21333221001 is a deficient number, since it is larger than the sum of its proper divisors (11294058411).

21333221001 is a wasteful number, since it uses less digits than its factorization.

21333221001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 139432840 (or 139432837 counting only the distinct ones).

The product of its (nonzero) digits is 216, while the sum is 18.

Adding to 21333221001 its reverse (10012233312), we get a palindrome (31345454313).

The spelling of 21333221001 in words is "twenty-one billion, three hundred thirty-three million, two hundred twenty-one thousand, one".