1808143 has 4 divisors (see below), whose sum is σ = 1813248. Its totient is φ = 1803040.

The previous prime is 1808119. The next prime is 1808161. The reversal of 1808143 is 3418081.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 3418081 = 19 ⋅179899.

It is a cyclic number.

It is not a de Polignac number, because 1808143 - 2¹³ = 1799951 is a prime.

It is a super-2 number, since 2×1808143² = 6538762216898, 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 (1808243) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1978 + ... + 2743.

It is an arithmetic number, because the mean of its divisors is an integer number (453312).

2^1808143 is an apocalyptic number.

1808143 is a deficient number, since it is larger than the sum of its proper divisors (5105).

1808143 is an equidigital number, since it uses as much as digits as its factorization.

1808143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5104.

The product of its (nonzero) digits is 768, while the sum is 25.

The square root of 1808143 is about 1344.6720789843. The cubic root of 1808143 is about 121.8271986987.

The spelling of 1808143 in words is "one million, eight hundred eight thousand, one hundred forty-three".