21244023 has 12 divisors (see below), whose sum is σ = 30730128. Its totient is φ = 14142240.

The previous prime is 21244001. The next prime is 21244061. The reversal of 21244023 is 32044212.

It is not a de Polignac number, because 21244023 - 2¹⁰ = 21242999 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21243987 and 21244005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21244063) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7483 + ... + 9923.

It is an arithmetic number, because the mean of its divisors is an integer number (2560844).

Almost surely, 2^21244023 is an apocalyptic number.

21244023 is a deficient number, since it is larger than the sum of its proper divisors (9486105).

21244023 is a wasteful number, since it uses less digits than its factorization.

21244023 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3414 (or 3411 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 18.

The square root of 21244023 is about 4609.1238863801. The cubic root of 21244023 is about 276.9569413536.

Adding to 21244023 its reverse (32044212), we get a palindrome (53288235).

The spelling of 21244023 in words is "twenty-one million, two hundred forty-four thousand, twenty-three".