21444039 has 6 divisors (see below), whose sum is σ = 30974736. Its totient is φ = 14296020.

The previous prime is 21444023. The next prime is 21444043. The reversal of 21444039 is 93044412.

21444039 is a `hidden beast` number, since 214 + 440 + 3 + 9 = 666.

It is not a de Polignac number, because 21444039 - 2⁴ = 21444023 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21444019) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1191327 + ... + 1191344.

It is an arithmetic number, because the mean of its divisors is an integer number (5162456).

Almost surely, 2^21444039 is an apocalyptic number.

21444039 is a deficient number, since it is larger than the sum of its proper divisors (9530697).

21444039 is a wasteful number, since it uses less digits than its factorization.

21444039 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2382677 (or 2382674 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 21444039 is about 4630.7708861484. The cubic root of 21444039 is about 277.8234261632.

It can be divided in two parts, 2144403 and 9, that added together give a palindrome (2144412).

The spelling of 21444039 in words is "twenty-one million, four hundred forty-four thousand, thirty-nine".