21004244 has 12 divisors (see below), whose sum is σ = 38355744. Its totient is φ = 10045464.

The previous prime is 21004241. The next prime is 21004261. The reversal of 21004244 is 44240012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21004241) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 114062 + ... + 114245.

It is an arithmetic number, because the mean of its divisors is an integer number (3196312).

Almost surely, 2^21004244 is an apocalyptic number.

It is an amenable number.

21004244 is a deficient number, since it is larger than the sum of its proper divisors (17351500).

21004244 is a wasteful number, since it uses less digits than its factorization.

21004244 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 228334 (or 228332 counting only the distinct ones).

The product of its (nonzero) digits is 256, while the sum is 17.

The square root of 21004244 is about 4583.0387299258. The cubic root of 21004244 is about 275.9110019008.

Adding to 21004244 its reverse (44240012), we get a palindrome (65244256).

The spelling of 21004244 in words is "twenty-one million, four thousand, two hundred forty-four".