21311331423 has 8 divisors (see below), whose sum is σ = 28417605168. Its totient is φ = 14206305984.

The previous prime is 21311331337. The next prime is 21311331443. The reversal of 21311331423 is 32413311312.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21311331423 - 2¹⁰ = 21311330399 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21311331393 and 21311331402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21311331443) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 271486 + ... + 341067.

It is an arithmetic number, because the mean of its divisors is an integer number (3552200646).

Almost surely, 2^21311331423 is an apocalyptic number.

21311331423 is a deficient number, since it is larger than the sum of its proper divisors (7106273745).

21311331423 is a wasteful number, since it uses less digits than its factorization.

21311331423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 624153.

The product of its digits is 1296, while the sum is 24.

Adding to 21311331423 its reverse (32413311312), we get a palindrome (53724642735).

The spelling of 21311331423 in words is "twenty-one billion, three hundred eleven million, three hundred thirty-one thousand, four hundred twenty-three".