20495 has 4 divisors (see below), whose sum is σ = 24600. Its totient is φ = 16392.

The previous prime is 20483. The next prime is 20507. The reversal of 20495 is 59402.

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

It is an interprime number because it is at equal distance from previous prime (20483) and next prime (20507).

It is a cyclic number.

It is not a de Polignac number, because 20495 - 2⁴ = 20479 is a prime.

It is a zygodrome in base 4.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2045 + ... + 2054.

It is an arithmetic number, because the mean of its divisors is an integer number (6150).

2²⁰⁴⁹⁵ is an apocalyptic number.

20495 is a deficient number, since it is larger than the sum of its proper divisors (4105).

20495 is an equidigital number, since it uses as much as digits as its factorization.

20495 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4104.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 20495 is about 143.1607488106. The cubic root of 20495 is about 27.3662931103.

Adding to 20495 its reverse (59402), we get a palindrome (79897).

It can be divided in two parts, 20 and 495, that added together give a palindrome (515).

The spelling of 20495 in words is "twenty thousand, four hundred ninety-five".