21744123 has 8 divisors (see below), whose sum is σ = 29775888. Its totient is φ = 14104224.

The previous prime is 21744119. The next prime is 21744137. The reversal of 21744123 is 32144712.

It is a happy number.

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

It is not a de Polignac number, because 21744123 - 2² = 21744119 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21744093 and 21744102.

It is not an unprimeable number, because it can be changed into a prime (21744143) 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, 97836 + ... + 98057.

It is an arithmetic number, because the mean of its divisors is an integer number (3721986).

Almost surely, 2^21744123 is an apocalyptic number.

21744123 is a deficient number, since it is larger than the sum of its proper divisors (8031765).

21744123 is a wasteful number, since it uses less digits than its factorization.

21744123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 195933.

The product of its digits is 1344, while the sum is 24.

The square root of 21744123 is about 4663.0594034389. The cubic root of 21744123 is about 279.1133646014.

Adding to 21744123 its reverse (32144712), we get a palindrome (53888835).

The spelling of 21744123 in words is "twenty-one million, seven hundred forty-four thousand, one hundred twenty-three".