20547 has 8 divisors (see below), whose sum is σ = 30480. Its totient is φ = 13680.

The previous prime is 20543. The next prime is 20549. The reversal of 20547 is 74502.

It is a happy number.

It is not a de Polignac number, because 20547 - 2² = 20543 is a prime.

It is a plaindrome in base 11.

It is a nialpdrome in base 12.

It is not an unprimeable number, because it can be changed into a prime (20543) 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, 354 + ... + 407.

It is an arithmetic number, because the mean of its divisors is an integer number (3810).

2²⁰⁵⁴⁷ is an apocalyptic number.

20547 is a gapful number since it is divisible by the number (27) formed by its first and last digit.

20547 is a deficient number, since it is larger than the sum of its proper divisors (9933).

20547 is an equidigital number, since it uses as much as digits as its factorization.

20547 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 770 (or 764 counting only the distinct ones).

The product of its (nonzero) digits is 280, while the sum is 18.

The square root of 20547 is about 143.3422477848. The cubic root of 20547 is about 27.3894181882.

It can be divided in two parts, 205 and 47, that added together give a palindrome (252).

The spelling of 20547 in words is "twenty thousand, five hundred forty-seven".