21333333331 has 4 divisors (see below), whose sum is σ = 21369309192. Its totient is φ = 21297357472.

The previous prime is 21333333317. The next prime is 21333333341. The reversal of 21333333331 is 13333333312.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21333333331 - 2²⁹ = 20796462419 is a prime.

It is a super-2 number, since 2×21333333331² (a number of 21 digits) contains 22 as substring.

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 21333333331.

It is not an unprimeable number, because it can be changed into a prime (21333333341) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17987041 + ... + 17988226.

It is an arithmetic number, because the mean of its divisors is an integer number (5342327298).

Almost surely, 2^21333333331 is an apocalyptic number.

21333333331 is a deficient number, since it is larger than the sum of its proper divisors (35975861).

21333333331 is an equidigital number, since it uses as much as digits as its factorization.

21333333331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35975860.

The product of its digits is 13122, while the sum is 28.

Adding to 21333333331 its reverse (13333333312), we get a palindrome (34666666643).

It can be divided in two parts, 2 and 1333333331, that multiplied together give a palindrome (2666666662).

The spelling of 21333333331 in words is "twenty-one billion, three hundred thirty-three million, three hundred thirty-three thousand, three hundred thirty-one".