21111311233 has 4 divisors (see below), whose sum is σ = 21121448368. Its totient is φ = 21101174100.

The previous prime is 21111311227. The next prime is 21111311239. The reversal of 21111311233 is 33211311112.

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 an interprime number because it is at equal distance from previous prime (21111311227) and next prime (21111311239).

It is a cyclic number.

It is not a de Polignac number, because 21111311233 - 2²⁵ = 21077756801 is a prime.

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 21111311233.

It is not an unprimeable number, because it can be changed into a prime (21111311239) 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, 5065443 + ... + 5069608.

It is an arithmetic number, because the mean of its divisors is an integer number (5280362092).

Almost surely, 2^21111311233 is an apocalyptic number.

It is an amenable number.

21111311233 is a deficient number, since it is larger than the sum of its proper divisors (10137135).

21111311233 is a wasteful number, since it uses less digits than its factorization.

21111311233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10137134.

The product of its digits is 108, while the sum is 19.

Adding to 21111311233 its reverse (33211311112), we get a palindrome (54322622345).

The spelling of 21111311233 in words is "twenty-one billion, one hundred eleven million, three hundred eleven thousand, two hundred thirty-three".