20279 has 4 divisors (see below), whose sum is σ = 23184. Its totient is φ = 17376.

The previous prime is 20269. The next prime is 20287. The reversal of 20279 is 97202.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 20279 - 2⁸ = 20023 is a prime.

It is a super-2 number, since 2×20279² = 822475682, which contains 22 as substring.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 20279.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20219) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1442 + ... + 1455.

It is an arithmetic number, because the mean of its divisors is an integer number (5796).

2²⁰²⁷⁹ is an apocalyptic number.

20279 is a deficient number, since it is larger than the sum of its proper divisors (2905).

20279 is an equidigital number, since it uses as much as digits as its factorization.

20279 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2904.

The product of its (nonzero) digits is 252, while the sum is 20.

The square root of 20279 is about 142.4043538660. The cubic root of 20279 is about 27.2698141670.

The spelling of 20279 in words is "twenty thousand, two hundred seventy-nine".