21117189 has 8 divisors (see below), whose sum is σ = 29638240. Its totient is φ = 13337136.

The previous prime is 21117137. The next prime is 21117193. The reversal of 21117189 is 98171112.

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

It is not a de Polignac number, because 21117189 - 2⁸ = 21116933 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21110189) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 185182 + ... + 185295.

It is an arithmetic number, because the mean of its divisors is an integer number (3704780).

Almost surely, 2^21117189 is an apocalyptic number.

It is an amenable number.

21117189 is a deficient number, since it is larger than the sum of its proper divisors (8521051).

21117189 is a wasteful number, since it uses less digits than its factorization.

21117189 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 370499.

The product of its digits is 1008, while the sum is 30.

The square root of 21117189 is about 4595.3442743716. The cubic root of 21117189 is about 276.4046652727.

The spelling of 21117189 in words is "twenty-one million, one hundred seventeen thousand, one hundred eighty-nine".