21044023 has 16 divisors (see below), whose sum is σ = 28256256. Its totient is φ = 15135840.

The previous prime is 21044003. The next prime is 21044047. The reversal of 21044023 is 32044012.

It is a cyclic number.

It is not a de Polignac number, because 21044023 - 2⁵ = 21043991 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21043988 and 21044006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21044003) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9511 + ... + 11512.

It is an arithmetic number, because the mean of its divisors is an integer number (1766016).

Almost surely, 2^21044023 is an apocalyptic number.

21044023 is a deficient number, since it is larger than the sum of its proper divisors (7212233).

21044023 is a wasteful number, since it uses less digits than its factorization.

21044023 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21054.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21044023 is about 4587.3764833508. The cubic root of 21044023 is about 276.0850705697.

Adding to 21044023 its reverse (32044012), we get a palindrome (53088035).

The spelling of 21044023 in words is "twenty-one million, forty-four thousand, twenty-three".