20601 has 16 divisors (see below), whose sum is σ = 35200. Its totient is φ = 11664.

The previous prime is 20599. The next prime is 20611. The reversal of 20601 is 10602.

It is not a de Polignac number, because 20601 - 2¹ = 20599 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (20611) 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 15 ways as a sum of consecutive naturals, for example, 135 + ... + 243.

It is an arithmetic number, because the mean of its divisors is an integer number (2200).

2²⁰⁶⁰¹ is an apocalyptic number.

20601 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

20601 is a deficient number, since it is larger than the sum of its proper divisors (14599).

20601 is a wasteful number, since it uses less digits than its factorization.

20601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 125 (or 119 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

The square root of 20601 is about 143.5304845669. The cubic root of 20601 is about 27.4133914330.

Subtracting from 20601 its reverse (10602), we obtain a palindrome (9999).

The spelling of 20601 in words is "twenty thousand, six hundred one".