20138503 has 16 divisors (see below), whose sum is σ = 25724160. Its totient is φ = 15307200.

The previous prime is 20138453. The next prime is 20138507. The reversal of 20138503 is 30583102.

It is a cyclic number.

It is not a de Polignac number, because 20138503 - 2²¹ = 18041351 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20138507) 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 15 ways as a sum of consecutive naturals, for example, 33 + ... + 6346.

It is an arithmetic number, because the mean of its divisors is an integer number (1607760).

Almost surely, 2^20138503 is an apocalyptic number.

20138503 is a deficient number, since it is larger than the sum of its proper divisors (5585657).

20138503 is a wasteful number, since it uses less digits than its factorization.

20138503 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6438.

The product of its (nonzero) digits is 720, while the sum is 22.

The square root of 20138503 is about 4487.5943444122. The cubic root of 20138503 is about 272.0669124236.

The spelling of 20138503 in words is "twenty million, one hundred thirty-eight thousand, five hundred three".