21204675 has 36 divisors (see below), whose sum is σ = 38530024. Its totient is φ = 11145600.

The previous prime is 21204641. The next prime is 21204679. The reversal of 21204675 is 57640212.

It is not a de Polignac number, because 21204675 - 2⁸ = 21204419 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21204679) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 15780 + ... + 17070.

Almost surely, 2^21204675 is an apocalyptic number.

21204675 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21204675 is a deficient number, since it is larger than the sum of its proper divisors (17325349).

21204675 is a wasteful number, since it uses less digits than its factorization.

21204675 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1380 (or 1372 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 27.

The square root of 21204675 is about 4604.8534178625. The cubic root of 21204675 is about 276.7858432386.

Adding to 21204675 its reverse (57640212), we get a palindrome (78844887).

The spelling of 21204675 in words is "twenty-one million, two hundred four thousand, six hundred seventy-five".