21608489 has 8 divisors (see below), whose sum is σ = 25270080. Its totient is φ = 18090576.

The previous prime is 21608467. The next prime is 21608497. The reversal of 21608489 is 98480612.

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

It is not a de Polignac number, because 21608489 - 2⁸ = 21608233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21608429) 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, 35594 + ... + 36195.

It is an arithmetic number, because the mean of its divisors is an integer number (3158760).

Almost surely, 2^21608489 is an apocalyptic number.

It is an amenable number.

21608489 is a deficient number, since it is larger than the sum of its proper divisors (3661591).

21608489 is an equidigital number, since it uses as much as digits as its factorization.

21608489 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 71839.

The product of its (nonzero) digits is 27648, while the sum is 38.

The square root of 21608489 is about 4648.4931967251. The cubic root of 21608489 is about 278.5318089861.

The spelling of 21608489 in words is "twenty-one million, six hundred eight thousand, four hundred eighty-nine".