20445564 has 24 divisors (see below), whose sum is σ = 48722688. Its totient is φ = 6670000.

The previous prime is 20445541. The next prime is 20445583. The reversal of 20445564 is 46554402.

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 7 ways as a sum of consecutive naturals, for example, 17562 + ... + 18689.

It is an arithmetic number, because the mean of its divisors is an integer number (2030112).

Almost surely, 2^20445564 is an apocalyptic number.

It is an amenable number.

20445564 is an abundant number, since it is smaller than the sum of its proper divisors (28277124).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20445564 is a wasteful number, since it uses less digits than its factorization.

20445564 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 36305 (or 36303 counting only the distinct ones).

The product of its (nonzero) digits is 19200, while the sum is 30.

The square root of 20445564 is about 4521.6771224845. The cubic root of 20445564 is about 273.4427197850.

Adding to 20445564 its reverse (46554402), we get a palindrome (66999966).

The spelling of 20445564 in words is "twenty million, four hundred forty-five thousand, five hundred sixty-four".