20605045 has 4 divisors (see below), whose sum is σ = 24726060. Its totient is φ = 16484032.

The previous prime is 20605043. The next prime is 20605069. The reversal of 20605045 is 54050602.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 54050602 = 2 ⋅27025301.

It can be written as a sum of positive squares in 2 ways, for example, as 9375844 + 11229201 = 3062^2 + 3351^2 .

It is a cyclic number.

It is not a de Polignac number, because 20605045 - 2¹ = 20605043 is a prime.

It is a Smith number, since the sum of its digits (22) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20605043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2060500 + ... + 2060509.

It is an arithmetic number, because the mean of its divisors is an integer number (6181515).

Almost surely, 2^20605045 is an apocalyptic number.

It is an amenable number.

20605045 is a deficient number, since it is larger than the sum of its proper divisors (4121015).

20605045 is an equidigital number, since it uses as much as digits as its factorization.

20605045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4121014.

The product of its (nonzero) digits is 1200, while the sum is 22.

The square root of 20605045 is about 4539.2780262945. The cubic root of 20605045 is about 274.1518551920.

Adding to 20605045 its reverse (54050602), we get a palindrome (74655647).

The spelling of 20605045 in words is "twenty million, six hundred five thousand, forty-five".