20597 has 4 divisors (see below), whose sum is σ = 21120.
Its totient is φ = 20076.
The previous prime is 20593. The next prime is 20599. The reversal of 20597 is 79502.
It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.
It is a cyclic number.
It is not a de Polignac number, because 20597 - 22 = 20593 is a prime.
It is a Duffinian number.
It is a congruent number.
It is not an unprimeable number, because it can be changed into a prime (20593) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (7) of ones.
It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 197 + ... + 282.
It is an arithmetic number, because the mean of its divisors is an integer number (5280).
220597 is an apocalyptic number.
It is an amenable number.
20597 is a deficient number, since it is larger than the sum of its proper divisors (523).
20597 is an equidigital number, since it uses as much as digits as its factorization.
20597 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 522.
The product of its (nonzero) digits is 630, while the sum is 23.
The square root of 20597 is about 143.5165495683.
The cubic root of 20597 is about 27.4116170747.
The spelling of 20597 in words is "twenty thousand, five hundred ninety-seven".