21202604 has 12 divisors (see below), whose sum is σ = 39287304. Its totient is φ = 9977664.

The previous prime is 21202603. The next prime is 21202609. The reversal of 21202604 is 40620212.

It is a Harshad number since it is a multiple of its sum of digits (17).

It is not an unprimeable number, because it can be changed into a prime (21202603) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 155834 + ... + 155969.

It is an arithmetic number, because the mean of its divisors is an integer number (3273942).

Almost surely, 2^21202604 is an apocalyptic number.

It is an amenable number.

21202604 is a deficient number, since it is larger than the sum of its proper divisors (18084700).

21202604 is a wasteful number, since it uses less digits than its factorization.

21202604 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 311824 (or 311822 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 17.

The square root of 21202604 is about 4604.6285409357. The cubic root of 21202604 is about 276.7768319845.

Adding to 21202604 its reverse (40620212), we get a palindrome (61822816).

The spelling of 21202604 in words is "twenty-one million, two hundred two thousand, six hundred four".