21170404 has 12 divisors (see below), whose sum is σ = 37203628. Its totient is φ = 10540800.

The previous prime is 21170399. The next prime is 21170407. The reversal of 21170404 is 40407112.

It can be written as a sum of positive squares in 2 ways, for example, as 16321600 + 4848804 = 4040^2 + 2202^2 .

It is not an unprimeable number, because it can be changed into a prime (21170407) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 10017 + ... + 11944.

Almost surely, 2^21170404 is an apocalyptic number.

It is an amenable number.

21170404 is a deficient number, since it is larger than the sum of its proper divisors (16033224).

21170404 is a wasteful number, since it uses less digits than its factorization.

21170404 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22206 (or 22204 counting only the distinct ones).

The product of its (nonzero) digits is 224, while the sum is 19.

The square root of 21170404 is about 4601.1307305922. The cubic root of 21170404 is about 276.6366490553.

Adding to 21170404 its reverse (40407112), we get a palindrome (61577516).

The spelling of 21170404 in words is "twenty-one million, one hundred seventy thousand, four hundred four".