20228605 has 4 divisors (see below), whose sum is σ = 24274332. Its totient is φ = 16182880.

The previous prime is 20228587. The next prime is 20228639. The reversal of 20228605 is 50682202.

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 15856324 + 4372281 = 3982^2 + 2091^2 .

It is not a de Polignac number, because 20228605 - 2⁹ = 20228093 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20228605.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2022856 + ... + 2022865.

It is an arithmetic number, because the mean of its divisors is an integer number (6068583).

Almost surely, 2^20228605 is an apocalyptic number.

It is an amenable number.

20228605 is a deficient number, since it is larger than the sum of its proper divisors (4045727).

20228605 is an equidigital number, since it uses as much as digits as its factorization.

20228605 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4045726.

The product of its (nonzero) digits is 1920, while the sum is 25.

The square root of 20228605 is about 4497.6221495364. The cubic root of 20228605 is about 272.4720617767.

The spelling of 20228605 in words is "twenty million, two hundred twenty-eight thousand, six hundred five".