20820503 has 4 divisors (see below), whose sum is σ = 22713288. Its totient is φ = 18927720.

The previous prime is 20820491. The next prime is 20820509. The reversal of 20820503 is 30502802.

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 20820503 - 2²⁴ = 4043287 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20820509) 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, 946376 + ... + 946397.

It is an arithmetic number, because the mean of its divisors is an integer number (5678322).

Almost surely, 2^20820503 is an apocalyptic number.

20820503 is a deficient number, since it is larger than the sum of its proper divisors (1892785).

20820503 is a wasteful number, since it uses less digits than its factorization.

20820503 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1892784.

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 20820503 is about 4562.9489368171. The cubic root of 20820503 is about 275.1041060384.

It can be divided in two parts, 208 and 20503, that multiplied together give a palindrome (4264624).

The spelling of 20820503 in words is "twenty million, eight hundred twenty thousand, five hundred three".