21814423 has 4 divisors (see below), whose sum is σ = 22404040. Its totient is φ = 21224808.

The previous prime is 21814399. The next prime is 21814433. The reversal of 21814423 is 32441812.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21814423 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 (21814433) 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, 294753 + ... + 294826.

It is an arithmetic number, because the mean of its divisors is an integer number (5601010).

Almost surely, 2^21814423 is an apocalyptic number.

21814423 is a deficient number, since it is larger than the sum of its proper divisors (589617).

21814423 is an equidigital number, since it uses as much as digits as its factorization.

21814423 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 589616.

The product of its digits is 1536, while the sum is 25.

The square root of 21814423 is about 4670.5912901901. The cubic root of 21814423 is about 279.4138375374.

It can be divided in two parts, 218 and 14423, that added together give a palindrome (14641).

The spelling of 21814423 in words is "twenty-one million, eight hundred fourteen thousand, four hundred twenty-three".