20145503 has 4 divisors (see below), whose sum is σ = 23023440. Its totient is φ = 17267568.

The previous prime is 20145487. The next prime is 20145509. The reversal of 20145503 is 30554102.

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 20145503 - 2⁴ = 20145487 is a prime.

It is a super-2 number, since 2×20145503² = 811682582246018, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20145509) 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, 1438958 + ... + 1438971.

It is an arithmetic number, because the mean of its divisors is an integer number (5755860).

Almost surely, 2^20145503 is an apocalyptic number.

20145503 is a deficient number, since it is larger than the sum of its proper divisors (2877937).

20145503 is an equidigital number, since it uses as much as digits as its factorization.

20145503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2877936.

The product of its (nonzero) digits is 600, while the sum is 20.

The square root of 20145503 is about 4488.3742045422. The cubic root of 20145503 is about 272.0984316113.

Adding to 20145503 its reverse (30554102), we get a palindrome (50699605).

The spelling of 20145503 in words is "twenty million, one hundred forty-five thousand, five hundred three".