20445565 has 16 divisors (see below), whose sum is σ = 28517760. Its totient is φ = 13780800.

The previous prime is 20445541. The next prime is 20445583. The reversal of 20445565 is 56554402.

It is not a de Polignac number, because 20445565 - 2⁵ = 20445533 is a prime.

It is a super-2 number, since 2×20445565² = 836042256338450, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2886 + ... + 7015.

It is an arithmetic number, because the mean of its divisors is an integer number (1782360).

Almost surely, 2^20445565 is an apocalyptic number.

It is an amenable number.

20445565 is a deficient number, since it is larger than the sum of its proper divisors (8072195).

20445565 is an equidigital number, since it uses as much as digits as its factorization.

20445565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9972.

The product of its (nonzero) digits is 24000, while the sum is 31.

The square root of 20445565 is about 4521.6772330630. The cubic root of 20445565 is about 273.4427242430.

Adding to 20445565 its reverse (56554402), we get a palindrome (76999967).

The spelling of 20445565 in words is "twenty million, four hundred forty-five thousand, five hundred sixty-five".