21124604 has 6 divisors (see below), whose sum is σ = 36968064. Its totient is φ = 10562300.

The previous prime is 21124601. The next prime is 21124619. The reversal of 21124604 is 40642112.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21124601) 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 as a sum of consecutive naturals, namely, 2640572 + ... + 2640579.

It is an arithmetic number, because the mean of its divisors is an integer number (6161344).

Almost surely, 2^21124604 is an apocalyptic number.

It is an amenable number.

21124604 is a deficient number, since it is larger than the sum of its proper divisors (15843460).

21124604 is a wasteful number, since it uses less digits than its factorization.

21124604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5281155 (or 5281153 counting only the distinct ones).

The product of its (nonzero) digits is 384, while the sum is 20.

The square root of 21124604 is about 4596.1509983898. The cubic root of 21124604 is about 276.4370133400.

Adding to 21124604 its reverse (40642112), we get a palindrome (61766716).

The spelling of 21124604 in words is "twenty-one million, one hundred twenty-four thousand, six hundred four".