21342112423 has 4 divisors (see below), whose sum is σ = 21425155920. Its totient is φ = 21259068928.

The previous prime is 21342112381. The next prime is 21342112433. The reversal of 21342112423 is 32421124312.

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 21342112423 - 2¹⁷ = 21341981351 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 (21342112433) 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, 41521363 + ... + 41521876.

It is an arithmetic number, because the mean of its divisors is an integer number (5356288980).

Almost surely, 2^21342112423 is an apocalyptic number.

21342112423 is a deficient number, since it is larger than the sum of its proper divisors (83043497).

21342112423 is an equidigital number, since it uses as much as digits as its factorization.

21342112423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 83043496.

The product of its digits is 2304, while the sum is 25.

Adding to 21342112423 its reverse (32421124312), we get a palindrome (53763236735).

The spelling of 21342112423 in words is "twenty-one billion, three hundred forty-two million, one hundred twelve thousand, four hundred twenty-three".