21063204 has 72 divisors (see below), whose sum is σ = 57028608. Its totient is φ = 6531840.

The previous prime is 21063199. The next prime is 21063223. The reversal of 21063204 is 40236012.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 77589 + ... + 77859.

It is an arithmetic number, because the mean of its divisors is an integer number (792064).

Almost surely, 2^21063204 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21063204, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28514304).

21063204 is an abundant number, since it is smaller than the sum of its proper divisors (35965404).

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

21063204 is a wasteful number, since it uses less digits than its factorization.

21063204 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 425 (or 420 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 21063204 is about 4589.4666356778. The cubic root of 21063204 is about 276.1689262030.

Adding to 21063204 its reverse (40236012), we get a palindrome (61299216).

The spelling of 21063204 in words is "twenty-one million, sixty-three thousand, two hundred four".