43209409 has 4 divisors (see below), whose sum is σ = 43224516. Its totient is φ = 43194304.

The previous prime is 43209379. The next prime is 43209421. The reversal of 43209409 is 90490234.

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

It can be written as a sum of positive squares in 2 ways, for example, as 10112400 + 33097009 = 3180^2 + 5753^2 .

It is a cyclic number.

It is not a de Polignac number, because 43209409 - 2¹³ = 43201217 is a prime.

It is a super-2 number, since 2×43209409² = 3734106052258562, which contains 22 as substring.

It is a Smith number, since the sum of its digits (31) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43209809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1804 + ... + 9469.

It is an arithmetic number, because the mean of its divisors is an integer number (10806129).

Almost surely, 2^43209409 is an apocalyptic number.

It is an amenable number.

43209409 is a deficient number, since it is larger than the sum of its proper divisors (15107).

43209409 is a wasteful number, since it uses less digits than its factorization.

43209409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15106.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 43209409 is about 6573.3864179736. The cubic root of 43209409 is about 350.9076008872.

The spelling of 43209409 in words is "forty-three million, two hundred nine thousand, four hundred nine".