20408263 has 2 divisors, whose sum is σ = 20408264. Its totient is φ = 20408262.

The previous prime is 20408243. The next prime is 20408303. The reversal of 20408263 is 36280402.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20408263 - 2⁵ = 20408231 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20408243) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10204131 + 10204132.

It is an arithmetic number, because the mean of its divisors is an integer number (10204132).

Almost surely, 2^20408263 is an apocalyptic number.

20408263 is a deficient number, since it is larger than the sum of its proper divisors (1).

20408263 is an equidigital number, since it uses as much as digits as its factorization.

20408263 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 25.

The square root of 20408263 is about 4517.5505531206. The cubic root of 20408263 is about 273.2763284189.

Adding to 20408263 its reverse (36280402), we get a palindrome (56688665).

The spelling of 20408263 in words is "twenty million, four hundred eight thousand, two hundred sixty-three".