20565597 has 16 divisors (see below), whose sum is σ = 31268160. Its totient is φ = 11910912.

The previous prime is 20565577. The next prime is 20565607. The reversal of 20565597 is 79556502.

It is not a de Polignac number, because 20565597 - 2⁶ = 20565533 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (39).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20565527) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 14847 + ... + 16172.

It is an arithmetic number, because the mean of its divisors is an integer number (1954260).

Almost surely, 2^20565597 is an apocalyptic number.

It is an amenable number.

20565597 is a deficient number, since it is larger than the sum of its proper divisors (10702563).

20565597 is a wasteful number, since it uses less digits than its factorization.

20565597 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31052.

The product of its (nonzero) digits is 94500, while the sum is 39.

The square root of 20565597 is about 4534.9307602212. The cubic root of 20565597 is about 273.9767904400.

The spelling of 20565597 in words is "twenty million, five hundred sixty-five thousand, five hundred ninety-seven".