21044123 has 4 divisors (see below), whose sum is σ = 21178320. Its totient is φ = 20909928.

The previous prime is 21044117. The next prime is 21044129. The reversal of 21044123 is 32144012.

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

It is an interprime number because it is at equal distance from previous prime (21044117) and next prime (21044129).

It is a cyclic number.

It is not a de Polignac number, because 21044123 - 2⁶ = 21044059 is a prime.

It is a super-2 number, since 2×21044123² = 885710225678258, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21044129) 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, 66863 + ... + 67176.

It is an arithmetic number, because the mean of its divisors is an integer number (5294580).

Almost surely, 2^21044123 is an apocalyptic number.

21044123 is a deficient number, since it is larger than the sum of its proper divisors (134197).

21044123 is a wasteful number, since it uses less digits than its factorization.

21044123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 134196.

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21044123 is about 4587.3873828139. The cubic root of 21044123 is about 276.0855078825.

Adding to 21044123 its reverse (32144012), we get a palindrome (53188135).

The spelling of 21044123 in words is "twenty-one million, forty-four thousand, one hundred twenty-three".