20565601 has 8 divisors (see below), whose sum is σ = 23889344. Its totient is φ = 17338320.

The previous prime is 20565577. The next prime is 20565607. The reversal of 20565601 is 10656502.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 20565601 - 2⁵ = 20565569 is a prime.

It is a super-3 number, since 3×20565601³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20565607) 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 7 ways as a sum of consecutive naturals, for example, 23655 + ... + 24508.

It is an arithmetic number, because the mean of its divisors is an integer number (2986168).

Almost surely, 2^20565601 is an apocalyptic number.

It is an amenable number.

20565601 is a deficient number, since it is larger than the sum of its proper divisors (3323743).

20565601 is an equidigital number, since it uses as much as digits as its factorization.

20565601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 48231.

The product of its (nonzero) digits is 1800, while the sum is 25.

The square root of 20565601 is about 4534.9312012422. The cubic root of 20565601 is about 273.9768082028.

Subtracting from 20565601 its reverse (10656502), we obtain a palindrome (9909099).

The spelling of 20565601 in words is "twenty million, five hundred sixty-five thousand, six hundred one".