21313231333 has 4 divisors (see below), whose sum is σ = 21313601280. Its totient is φ = 21312861388.

The previous prime is 21313231309. The next prime is 21313231343. The reversal of 21313231333 is 33313231312.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21313231333 - 2⁹ = 21313230821 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21313231298 and 21313231307.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21313231343) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 77893 + ... + 220666.

It is an arithmetic number, because the mean of its divisors is an integer number (5328400320).

Almost surely, 2^21313231333 is an apocalyptic number.

It is an amenable number.

21313231333 is a deficient number, since it is larger than the sum of its proper divisors (369947).

21313231333 is an equidigital number, since it uses as much as digits as its factorization.

21313231333 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 369946.

The product of its digits is 2916, while the sum is 25.

Adding to 21313231333 its reverse (33313231312), we get a palindrome (54626462645).

The spelling of 21313231333 in words is "twenty-one billion, three hundred thirteen million, two hundred thirty-one thousand, three hundred thirty-three".