21423344311 has 4 divisors (see below), whose sum is σ = 21423945352. Its totient is φ = 21422743272.

The previous prime is 21423344309. The next prime is 21423344347. The reversal of 21423344311 is 11344332412.

It is a happy number.

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 21423344311 - 2¹ = 21423344309 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 21423344311.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21423344351) 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, 243441 + ... + 319546.

It is an arithmetic number, because the mean of its divisors is an integer number (5355986338).

Almost surely, 2^21423344311 is an apocalyptic number.

21423344311 is a deficient number, since it is larger than the sum of its proper divisors (601041).

21423344311 is an equidigital number, since it uses as much as digits as its factorization.

21423344311 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 601040.

The product of its digits is 6912, while the sum is 28.

Adding to 21423344311 its reverse (11344332412), we get a palindrome (32767676723).

The spelling of 21423344311 in words is "twenty-one billion, four hundred twenty-three million, three hundred forty-four thousand, three hundred eleven".