21243044 has 12 divisors (see below), whose sum is σ = 37207884. Its totient is φ = 10612224.

The previous prime is 21243023. The next prime is 21243049. The reversal of 21243044 is 44034212.

It can be written as a sum of positive squares in 2 ways, for example, as 10758400 + 10484644 = 3280^2 + 3238^2 .

It is not an unprimeable number, because it can be changed into a prime (21243049) 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, 6752 + ... + 9384.

It is an arithmetic number, because the mean of its divisors is an integer number (3100657).

Almost surely, 2^21243044 is an apocalyptic number.

It is an amenable number.

21243044 is a deficient number, since it is larger than the sum of its proper divisors (15964840).

21243044 is a wasteful number, since it uses less digits than its factorization.

21243044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4654 (or 4652 counting only the distinct ones).

The product of its (nonzero) digits is 768, while the sum is 20.

The square root of 21243044 is about 4609.0176827606. The cubic root of 21243044 is about 276.9526869019.

Adding to 21243044 its reverse (44034212), we get a palindrome (65277256).

The spelling of 21243044 in words is "twenty-one million, two hundred forty-three thousand, forty-four".