43872809 has 4 divisors (see below), whose sum is σ = 44325204. Its totient is φ = 43420416.

The previous prime is 43872793. The next prime is 43872821. The reversal of 43872809 is 90827834.

43872809 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 90827834 = 2 ⋅45413917.

It can be written as a sum of positive squares in 2 ways, for example, as 29735209 + 14137600 = 5453^2 + 3760^2 .

It is a cyclic number.

It is not a de Polignac number, because 43872809 - 2⁴ = 43872793 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43872839) 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, 226052 + ... + 226245.

It is an arithmetic number, because the mean of its divisors is an integer number (11081301).

Almost surely, 2^43872809 is an apocalyptic number.

It is an amenable number.

43872809 is a deficient number, since it is larger than the sum of its proper divisors (452395).

43872809 is an equidigital number, since it uses as much as digits as its factorization.

43872809 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 452394.

The product of its (nonzero) digits is 96768, while the sum is 41.

The square root of 43872809 is about 6623.6552597490. The cubic root of 43872809 is about 352.6943320925.

The spelling of 43872809 in words is "forty-three million, eight hundred seventy-two thousand, eight hundred nine".