21617189 has 8 divisors (see below), whose sum is σ = 23708160. Its totient is φ = 19547200.

The previous prime is 21617143. The next prime is 21617191. The reversal of 21617189 is 98171612.

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-21617189 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 (21617689) 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, 3044 + ... + 7245.

It is an arithmetic number, because the mean of its divisors is an integer number (2963520).

Almost surely, 2^21617189 is an apocalyptic number.

It is an amenable number.

21617189 is a deficient number, since it is larger than the sum of its proper divisors (2090971).

21617189 is a wasteful number, since it uses less digits than its factorization.

21617189 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10491.

The product of its digits is 6048, while the sum is 35.

The square root of 21617189 is about 4649.4288896595. The cubic root of 21617189 is about 278.5691847538.

The spelling of 21617189 in words is "twenty-one million, six hundred seventeen thousand, one hundred eighty-nine".