20143809 has 20 divisors (see below), whose sum is σ = 34391104. Its totient is φ = 11510424.

The previous prime is 20143807. The next prime is 20143811. The reversal of 20143809 is 90834102.

It is an interprime number because it is at equal distance from previous prime (20143807) and next prime (20143811).

It is not a de Polignac number, because 20143809 - 2¹ = 20143807 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20143801) 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 19 ways as a sum of consecutive naturals, for example, 17197 + ... + 18330.

Almost surely, 2^20143809 is an apocalyptic number.

It is an amenable number.

20143809 is a deficient number, since it is larger than the sum of its proper divisors (14247295).

20143809 is an equidigital number, since it uses as much as digits as its factorization.

20143809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 35546 (or 35537 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 20143809 is about 4488.1854908192. The cubic root of 20143809 is about 272.0908046377.

The spelling of 20143809 in words is "twenty million, one hundred forty-three thousand, eight hundred nine".