21444004 has 24 divisors (see below), whose sum is σ = 41465088. Its totient is φ = 9651840.

The previous prime is 21443999. The next prime is 21444011. The reversal of 21444004 is 40044412.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5292 + ... + 8419.

It is an arithmetic number, because the mean of its divisors is an integer number (1727712).

Almost surely, 2^21444004 is an apocalyptic number.

It is an amenable number.

21444004 is a deficient number, since it is larger than the sum of its proper divisors (20021084).

21444004 is a wasteful number, since it uses less digits than its factorization.

21444004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13755 (or 13753 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 19.

The square root of 21444004 is about 4630.7671070785. The cubic root of 21444004 is about 277.8232750128.

Adding to 21444004 its reverse (40044412), we get a palindrome (61488416).

The spelling of 21444004 in words is "twenty-one million, four hundred forty-four thousand, four".