21231223311 has 4 divisors (see below), whose sum is σ = 28308297752. Its totient is φ = 14154148872.

The previous prime is 21231223291. The next prime is 21231223393. The reversal of 21231223311 is 11332213212.

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

It is not a de Polignac number, because 21231223311 - 2⁷ = 21231223183 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21231223711) 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, 3538537216 + ... + 3538537221.

It is an arithmetic number, because the mean of its divisors is an integer number (7077074438).

Almost surely, 2^21231223311 is an apocalyptic number.

21231223311 is a deficient number, since it is larger than the sum of its proper divisors (7077074441).

21231223311 is an equidigital number, since it uses as much as digits as its factorization.

21231223311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7077074440.

The product of its digits is 432, while the sum is 21.

Adding to 21231223311 its reverse (11332213212), we get a palindrome (32563436523).

The spelling of 21231223311 in words is "twenty-one billion, two hundred thirty-one million, two hundred twenty-three thousand, three hundred eleven".