20453 has 4 divisors (see below), whose sum is σ = 20748. Its totient is φ = 20160.

The previous prime is 20443. The next prime is 20477. The reversal of 20453 is 35402.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 289 + 20164 = 17^2 + 142^2 .

It is a cyclic number.

It is not a de Polignac number, because 20453 - 2⁶ = 20389 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 20453.

It is not an unprimeable number, because it can be changed into a prime (20443) 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, 23 + ... + 203.

It is an arithmetic number, because the mean of its divisors is an integer number (5187).

2²⁰⁴⁵³ is an apocalyptic number.

It is an amenable number.

20453 is a deficient number, since it is larger than the sum of its proper divisors (295).

20453 is a wasteful number, since it uses less digits than its factorization.

20453 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 294.

The product of its (nonzero) digits is 120, while the sum is 14.

The square root of 20453 is about 143.0139853301. The cubic root of 20453 is about 27.3475865909.

Adding to 20453 its reverse (35402), we get a palindrome (55855).

It can be divided in two parts, 2045 and 3, that added together give a 11-th power (2048 = 2¹¹).

The spelling of 20453 in words is "twenty thousand, four hundred fifty-three".