21442004 has 12 divisors (see below), whose sum is σ = 37561524. Its totient is φ = 10710144.

The previous prime is 21441989. The next prime is 21442009. The reversal of 21442004 is 40024412.

It can be written as a sum of positive squares in 2 ways, for example, as 19624900 + 1817104 = 4430^2 + 1348^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21442009) 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, 3122 + ... + 7254.

It is an arithmetic number, because the mean of its divisors is an integer number (3130127).

Almost surely, 2^21442004 is an apocalyptic number.

It is an amenable number.

21442004 is a deficient number, since it is larger than the sum of its proper divisors (16119520).

21442004 is a wasteful number, since it uses less digits than its factorization.

21442004 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5434 (or 5432 counting only the distinct ones).

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

The square root of 21442004 is about 4630.5511551002. The cubic root of 21442004 is about 277.8146375738.

Adding to 21442004 its reverse (40024412), we get a palindrome (61466416).

The spelling of 21442004 in words is "twenty-one million, four hundred forty-two thousand, four".