43690909 has 4 divisors (see below), whose sum is σ = 43704640. Its totient is φ = 43677180.

The previous prime is 43690903. The next prime is 43690931. The reversal of 43690909 is 90909634.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 90909634 = 2 ⋅45454817.

It is a cyclic number.

It is not a de Polignac number, because 43690909 - 2⁷ = 43690781 is a prime.

It is an alternating number because its digits alternate between even and odd.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43690903) 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, 652 + ... + 9370.

It is an arithmetic number, because the mean of its divisors is an integer number (10926160).

Almost surely, 2^43690909 is an apocalyptic number.

It is an amenable number.

43690909 is a deficient number, since it is larger than the sum of its proper divisors (13731).

43690909 is an equidigital number, since it uses as much as digits as its factorization.

43690909 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13730.

The product of its (nonzero) digits is 52488, while the sum is 40.

The square root of 43690909 is about 6609.9099086145. The cubic root of 43690909 is about 352.2062243918.

The spelling of 43690909 in words is "forty-three million, six hundred ninety thousand, nine hundred nine".