20342143 has 4 divisors (see below), whose sum is σ = 21226608. Its totient is φ = 19457680.

The previous prime is 20342131. The next prime is 20342167. The reversal of 20342143 is 34124302.

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 20342143 - 2²¹ = 18244991 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20342143.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20342123) 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, 442198 + ... + 442243.

It is an arithmetic number, because the mean of its divisors is an integer number (5306652).

Almost surely, 2^20342143 is an apocalyptic number.

20342143 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

20342143 is a deficient number, since it is larger than the sum of its proper divisors (884465).

20342143 is an equidigital number, since it uses as much as digits as its factorization.

20342143 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 884464.

The product of its (nonzero) digits is 576, while the sum is 19.

The square root of 20342143 is about 4510.2264909869. The cubic root of 20342143 is about 272.9808830598.

Adding to 20342143 its reverse (34124302), we get a palindrome (54466445).

The spelling of 20342143 in words is "twenty million, three hundred forty-two thousand, one hundred forty-three".