20605489 has 4 divisors (see below), whose sum is σ = 20685924. Its totient is φ = 20525056.

The previous prime is 20605477. The next prime is 20605531. The reversal of 20605489 is 98450602.

It is a happy number.

20605489 is nontrivially palindromic in base 16.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 15800625 + 4804864 = 3975^2 + 2192^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20605489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20605289) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 39832 + ... + 40345.

It is an arithmetic number, because the mean of its divisors is an integer number (5171481).

Almost surely, 2^20605489 is an apocalyptic number.

It is an amenable number.

20605489 is a deficient number, since it is larger than the sum of its proper divisors (80435).

20605489 is an equidigital number, since it uses as much as digits as its factorization.

20605489 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80434.

The product of its (nonzero) digits is 17280, while the sum is 34.

The square root of 20605489 is about 4539.3269324868. The cubic root of 20605489 is about 274.1538243303.

The spelling of 20605489 in words is "twenty million, six hundred five thousand, four hundred eighty-nine".