21210163 has 8 divisors (see below), whose sum is σ = 23835168. Its totient is φ = 18727104.

The previous prime is 21210151. The next prime is 21210173. The reversal of 21210163 is 36101212.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21210163 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21210103) 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 7 ways as a sum of consecutive naturals, for example, 35170 + ... + 35767.

It is an arithmetic number, because the mean of its divisors is an integer number (2979396).

Almost surely, 2^21210163 is an apocalyptic number.

21210163 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

21210163 is a deficient number, since it is larger than the sum of its proper divisors (2625005).

21210163 is a wasteful number, since it uses less digits than its factorization.

21210163 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 70973.

The product of its (nonzero) digits is 72, while the sum is 16.

The square root of 21210163 is about 4605.4492723295. The cubic root of 21210163 is about 276.8097195722.

Adding to 21210163 its reverse (36101212), we get a palindrome (57311375).

The spelling of 21210163 in words is "twenty-one million, two hundred ten thousand, one hundred sixty-three".