21170210 has 32 divisors (see below), whose sum is σ = 40200192. Its totient is φ = 8015040.

The previous prime is 21170209. The next prime is 21170213. The reversal of 21170210 is 1207112.

It is not an unprimeable number, because it can be changed into a prime (21170213) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 13844 + ... + 15296.

It is an arithmetic number, because the mean of its divisors is an integer number (1256256).

Almost surely, 2^21170210 is an apocalyptic number.

21170210 is a deficient number, since it is larger than the sum of its proper divisors (19029982).

21170210 is a wasteful number, since it uses less digits than its factorization.

21170210 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1538.

The product of its (nonzero) digits is 28, while the sum is 14.

The square root of 21170210 is about 4601.1096487695. The cubic root of 21170210 is about 276.6358040443.

Adding to 21170210 its reverse (1207112), we get a palindrome (22377322).

The spelling of 21170210 in words is "twenty-one million, one hundred seventy thousand, two hundred ten".