20413 has 4 divisors (see below), whose sum is σ = 20700. Its totient is φ = 20128.

The previous prime is 20411. The next prime is 20431. The reversal of 20413 is 31402.

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 6724 + 13689 = 82^2 + 117^2 .

It is a cyclic number.

It is not a de Polignac number, because 20413 - 2¹ = 20411 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 12 and base 14.

It is a self number, because there is not a number n which added to its sum of digits gives 20413.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20411) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63 + ... + 211.

It is an arithmetic number, because the mean of its divisors is an integer number (5175).

2²⁰⁴¹³ is an apocalyptic number.

It is an amenable number.

20413 is a deficient number, since it is larger than the sum of its proper divisors (287).

20413 is a wasteful number, since it uses less digits than its factorization.

20413 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 286.

The product of its (nonzero) digits is 24, while the sum is 10.

The square root of 20413 is about 142.8740704257. The cubic root of 20413 is about 27.3297470343.

Adding to 20413 its reverse (31402), we get a palindrome (51815).

The spelling of 20413 in words is "twenty thousand, four hundred thirteen".