20247 has 8 divisors (see below), whose sum is σ = 28656. Its totient is φ = 12672.

The previous prime is 20233. The next prime is 20249. The reversal of 20247 is 74202.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 20247 - 2⁴ = 20231 is a prime.

It is a nialpdrome in base 12 and base 14.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20249) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 148 + ... + 249.

It is an arithmetic number, because the mean of its divisors is an integer number (3582).

2²⁰²⁴⁷ is an apocalyptic number.

20247 is a deficient number, since it is larger than the sum of its proper divisors (8409).

20247 is a wasteful number, since it uses less digits than its factorization.

20247 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417.

The product of its (nonzero) digits is 112, while the sum is 15.

The square root of 20247 is about 142.2919533916. The cubic root of 20247 is about 27.2554628108.

Adding to 20247 its reverse (74202), we get a palindrome (94449).

The spelling of 20247 in words is "twenty thousand, two hundred forty-seven", and thus it is an iban number.