20445805 has 16 divisors (see below), whose sum is σ = 26147520. Its totient is φ = 15303168.

The previous prime is 20445791. The next prime is 20445823. The reversal of 20445805 is 50854402.

It is a cyclic number.

It is not a de Polignac number, because 20445805 - 2⁵ = 20445773 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6589 + ... + 9181.

It is an arithmetic number, because the mean of its divisors is an integer number (1634220).

Almost surely, 2^20445805 is an apocalyptic number.

It is an amenable number.

20445805 is a deficient number, since it is larger than the sum of its proper divisors (5701715).

20445805 is a wasteful number, since it uses less digits than its factorization.

20445805 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2700.

The product of its (nonzero) digits is 6400, while the sum is 28.

The square root of 20445805 is about 4521.7037718099. The cubic root of 20445805 is about 273.4437941735.

The spelling of 20445805 in words is "twenty million, four hundred forty-five thousand, eight hundred five".