21316204 has 48 divisors (see below), whose sum is σ = 46328128. Its totient is φ = 8356608.

The previous prime is 21316201. The next prime is 21316223. The reversal of 21316204 is 40261312.

It is not an unprimeable number, because it can be changed into a prime (21316201) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 56962 + ... + 57334.

Almost surely, 2^21316204 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 21316204, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (23164064).

21316204 is an abundant number, since it is smaller than the sum of its proper divisors (25011924).

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

21316204 is a wasteful number, since it uses less digits than its factorization.

21316204 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 554 (or 552 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 19.

The square root of 21316204 is about 4616.9474764177. The cubic root of 21316204 is about 277.2702597616.

Adding to 21316204 its reverse (40261312), we get a palindrome (61577516).

The spelling of 21316204 in words is "twenty-one million, three hundred sixteen thousand, two hundred four".