21324004 has 48 divisors (see below), whose sum is σ = 42900480. Its totient is φ = 9192960.

The previous prime is 21323999. The next prime is 21324011. The reversal of 21324004 is 40042312.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111549 + ... + 111739.

It is an arithmetic number, because the mean of its divisors is an integer number (893760).

Almost surely, 2^21324004 is an apocalyptic number.

It is an amenable number.

21324004 is an abundant number, since it is smaller than the sum of its proper divisors (21576476).

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

21324004 is a wasteful number, since it uses less digits than its factorization.

21324004 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340 (or 338 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 21324004 is about 4617.7921131207. The cubic root of 21324004 is about 277.3040751052.

Adding to 21324004 its reverse (40042312), we get a palindrome (61366316).

The spelling of 21324004 in words is "twenty-one million, three hundred twenty-four thousand, four".