21333223231 has 4 divisors (see below), whose sum is σ = 21682948264. Its totient is φ = 20983498200.

The previous prime is 21333223229. The next prime is 21333223267. The reversal of 21333223231 is 13232233312.

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 21333223231 - 2¹ = 21333223229 is a prime.

It is a super-2 number, since 2×21333223231² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21333223196 and 21333223205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21333223031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 174862425 + ... + 174862546.

It is an arithmetic number, because the mean of its divisors is an integer number (5420737066).

Almost surely, 2^21333223231 is an apocalyptic number.

21333223231 is a deficient number, since it is larger than the sum of its proper divisors (349725033).

21333223231 is an equidigital number, since it uses as much as digits as its factorization.

21333223231 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 349725032.

The product of its digits is 3888, while the sum is 25.

Adding to 21333223231 its reverse (13232233312), we get a palindrome (34565456543).

The spelling of 21333223231 in words is "twenty-one billion, three hundred thirty-three million, two hundred twenty-three thousand, two hundred thirty-one".