20042143 has 4 divisors (see below), whose sum is σ = 21864168. Its totient is φ = 18220120.

The previous prime is 20042117. The next prime is 20042173. The reversal of 20042143 is 34124002.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20042143 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 (20042173) 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, 910996 + ... + 911017.

It is an arithmetic number, because the mean of its divisors is an integer number (5466042).

Almost surely, 2^20042143 is an apocalyptic number.

20042143 is a deficient number, since it is larger than the sum of its proper divisors (1822025).

20042143 is a wasteful number, since it uses less digits than its factorization.

20042143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1822024.

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

The square root of 20042143 is about 4476.8452061692. The cubic root of 20042143 is about 271.6322840717.

Adding to 20042143 its reverse (34124002), we get a palindrome (54166145).

The spelling of 20042143 in words is "twenty million, forty-two thousand, one hundred forty-three".