43809561 has 24 divisors (see below), whose sum is σ = 68571360. Its totient is φ = 26845056.

The previous prime is 43809553. The next prime is 43809617. The reversal of 43809561 is 16590834.

It is not a de Polignac number, because 43809561 - 2³ = 43809553 is a prime.

It is not an unprimeable number, because it can be changed into a prime (43808561) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 3250 + ... + 9908.

It is an arithmetic number, because the mean of its divisors is an integer number (2857140).

Almost surely, 2^43809561 is an apocalyptic number.

It is an amenable number.

43809561 is a deficient number, since it is larger than the sum of its proper divisors (24761799).

43809561 is a wasteful number, since it uses less digits than its factorization.

43809561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6725 (or 6722 counting only the distinct ones).

The product of its (nonzero) digits is 25920, while the sum is 36.

The square root of 43809561 is about 6618.8791347176. The cubic root of 43809561 is about 352.5247666317.

The spelling of 43809561 in words is "forty-three million, eight hundred nine thousand, five hundred sixty-one".