20812503 has 4 divisors (see below), whose sum is σ = 27750008. Its totient is φ = 13875000.

The previous prime is 20812483. The next prime is 20812511. The reversal of 20812503 is 30521802.

It is a semiprime because it is the product of two primes.

It is not a de Polignac number, because 20812503 - 2⁸ = 20812247 is a prime.

It is a super-2 number, since 2×20812503² = 866320562250018, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20812503.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20812513) 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, 3468748 + ... + 3468753.

It is an arithmetic number, because the mean of its divisors is an integer number (6937502).

Almost surely, 2^20812503 is an apocalyptic number.

20812503 is a deficient number, since it is larger than the sum of its proper divisors (6937505).

20812503 is an equidigital number, since it uses as much as digits as its factorization.

20812503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6937504.

The product of its (nonzero) digits is 480, while the sum is 21.

The square root of 20812503 is about 4562.0722265216. The cubic root of 20812503 is about 275.0688664993.

The spelling of 20812503 in words is "twenty million, eight hundred twelve thousand, five hundred three".