20666445 has 24 divisors (see below), whose sum is σ = 34025376. Its totient is φ = 10705632.

The previous prime is 20666413. The next prime is 20666447. The reversal of 20666445 is 54466602.

It is not a de Polignac number, because 20666445 - 2⁵ = 20666413 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20666447) 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 23 ways as a sum of consecutive naturals, for example, 115366 + ... + 115544.

It is an arithmetic number, because the mean of its divisors is an integer number (1417724).

Almost surely, 2^20666445 is an apocalyptic number.

It is an amenable number.

20666445 is a deficient number, since it is larger than the sum of its proper divisors (13358931).

20666445 is an equidigital number, since it uses as much as digits as its factorization.

20666445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 409 (or 230 counting only the distinct ones).

The product of its (nonzero) digits is 34560, while the sum is 33.

The square root of 20666445 is about 4546.0361855137. The cubic root of 20666445 is about 274.4238958768.

The spelling of 20666445 in words is "twenty million, six hundred sixty-six thousand, four hundred forty-five".