21144304 has 40 divisors (see below), whose sum is σ = 42594992. Its totient is φ = 10160640.

The previous prime is 21144301. The next prime is 21144307. The reversal of 21144304 is 40344112.

It is an interprime number because it is at equal distance from previous prime (21144301) and next prime (21144307).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21144301) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50014 + ... + 50434.

Almost surely, 2^21144304 is an apocalyptic number.

It is an amenable number.

21144304 is an abundant number, since it is smaller than the sum of its proper divisors (21450688).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21144304 is a wasteful number, since it uses less digits than its factorization.

21144304 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 545 (or 539 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 19.

The square root of 21144304 is about 4598.2935965421. The cubic root of 21144304 is about 276.5229181801.

Adding to 21144304 its reverse (40344112), we get a palindrome (61488416).

The spelling of 21144304 in words is "twenty-one million, one hundred forty-four thousand, three hundred four".