21440204 has 6 divisors (see below), whose sum is σ = 37520364. Its totient is φ = 10720100.

The previous prime is 21440203. The next prime is 21440207. The reversal of 21440204 is 40204412.

It is not an unprimeable number, because it can be changed into a prime (21440203) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2680022 + ... + 2680029.

It is an arithmetic number, because the mean of its divisors is an integer number (6253394).

Almost surely, 2^21440204 is an apocalyptic number.

It is an amenable number.

21440204 is a deficient number, since it is larger than the sum of its proper divisors (16080160).

21440204 is a wasteful number, since it uses less digits than its factorization.

21440204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5360055 (or 5360053 counting only the distinct ones).

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

The square root of 21440204 is about 4630.3567897085. The cubic root of 21440204 is about 277.8068634196.

Adding to 21440204 its reverse (40204412), we get a palindrome (61644616).

The spelling of 21440204 in words is "twenty-one million, four hundred forty thousand, two hundred four".