20502563 has 4 divisors (see below), whose sum is σ = 21163968. Its totient is φ = 19841160.

The previous prime is 20502553. The next prime is 20502569. The reversal of 20502563 is 36520502.

It is a happy number.

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 20502563 - 2¹⁸ = 20240419 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20502569) 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, 330656 + ... + 330717.

It is an arithmetic number, because the mean of its divisors is an integer number (5290992).

Almost surely, 2^20502563 is an apocalyptic number.

20502563 is a deficient number, since it is larger than the sum of its proper divisors (661405).

20502563 is an equidigital number, since it uses as much as digits as its factorization.

20502563 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 661404.

The product of its (nonzero) digits is 1800, while the sum is 23.

The square root of 20502563 is about 4527.9755962240. The cubic root of 20502563 is about 273.6965890390.

The spelling of 20502563 in words is "twenty million, five hundred two thousand, five hundred sixty-three".