21143604 has 24 divisors (see below), whose sum is σ = 49479808. Its totient is φ = 7027200.

The previous prime is 21143579. The next prime is 21143609. The reversal of 21143604 is 40634112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21143609) 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, 2004 + ... + 6804.

Almost surely, 2^21143604 is an apocalyptic number.

It is an amenable number.

21143604 is an abundant number, since it is smaller than the sum of its proper divisors (28336204).

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

21143604 is a wasteful number, since it uses less digits than its factorization.

21143604 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5175 (or 5173 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 21143604 is about 4598.2174807201. The cubic root of 21143604 is about 276.5198666383.

Adding to 21143604 its reverse (40634112), we get a palindrome (61777716).

The spelling of 21143604 in words is "twenty-one million, one hundred forty-three thousand, six hundred four".