43521409 has 8 divisors (see below), whose sum is σ = 44435520. Its totient is φ = 42613296.

The previous prime is 43521407. The next prime is 43521421. The reversal of 43521409 is 90412534.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 43521409 - 2¹ = 43521407 is a prime.

It is a super-2 number, since 2×43521409² = 3788226082690562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43521403) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15012 + ... + 17674.

It is an arithmetic number, because the mean of its divisors is an integer number (5554440).

Almost surely, 2^43521409 is an apocalyptic number.

It is an amenable number.

43521409 is a deficient number, since it is larger than the sum of its proper divisors (914111).

43521409 is a wasteful number, since it uses less digits than its factorization.

43521409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2999.

The product of its (nonzero) digits is 4320, while the sum is 28.

The square root of 43521409 is about 6597.0757915913. The cubic root of 43521409 is about 351.7501697691.

The spelling of 43521409 in words is "forty-three million, five hundred twenty-one thousand, four hundred nine".