20577 has 8 divisors (see below), whose sum is σ = 28960.
Its totient is φ = 12996.
The previous prime is 20563. The next prime is 20593. The reversal of 20577 is 77502.
It can be divided in two parts, 205 and 77, that added together give a palindrome (282).
It is an ABA number since it can be written as A⋅BA, here for A=3, B=19.
It is not a de Polignac number, because 20577 - 210 = 19553 is a prime.
It is a Duffinian number.
It is a nialpdrome in base 12.
It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 20577.
It is not an unprimeable number, because it can be changed into a prime (20507) by changing a digit.
It is a pernicious number, because its binary representation contains a prime number (5) of ones.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1074 + ... + 1092.
It is an arithmetic number, because the mean of its divisors is an integer number (3620).
220577 is an apocalyptic number.
It is an amenable number.
20577 is a deficient number, since it is larger than the sum of its proper divisors (8383).
20577 is an frugal number, since it uses more digits than its factorization.
20577 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 60 (or 22 counting only the distinct ones).
The product of its (nonzero) digits is 490, while the sum is 21.
The square root of 20577 is about 143.4468542701.
The cubic root of 20577 is about 27.4027418358.
The spelling of 20577 in words is "twenty thousand, five hundred seventy-seven".