20042431 has 4 divisors (see below), whose sum is σ = 20249152. Its totient is φ = 19835712.

The previous prime is 20042417. The next prime is 20042443. The reversal of 20042431 is 13424002.

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 20042431 - 2⁹ = 20041919 is a prime.

It is a super-3 number, since 3×20042431³ (a number of 23 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20042731) 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, 103215 + ... + 103408.

It is an arithmetic number, because the mean of its divisors is an integer number (5062288).

Almost surely, 2^20042431 is an apocalyptic number.

20042431 is a deficient number, since it is larger than the sum of its proper divisors (206721).

20042431 is an equidigital number, since it uses as much as digits as its factorization.

20042431 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 206720.

The product of its (nonzero) digits is 192, while the sum is 16.

The square root of 20042431 is about 4476.8773715616. The cubic root of 20042431 is about 271.6335851588.

Adding to 20042431 its reverse (13424002), we get a palindrome (33466433).

The spelling of 20042431 in words is "twenty million, forty-two thousand, four hundred thirty-one".