43591609 has 2 divisors, whose sum is σ = 43591610. Its totient is φ = 43591608.

The previous prime is 43591573. The next prime is 43591633. The reversal of 43591609 is 90619534.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 43033600 + 558009 = 6560^2 + 747^2 .

It is a cyclic number.

It is not a de Polignac number, because 43591609 - 2¹³ = 43583417 is a prime.

It is not a weakly prime, because it can be changed into another prime (43591649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21795804 + 21795805.

It is an arithmetic number, because the mean of its divisors is an integer number (21795805).

Almost surely, 2^43591609 is an apocalyptic number.

It is an amenable number.

43591609 is a deficient number, since it is larger than the sum of its proper divisors (1).

43591609 is an equidigital number, since it uses as much as digits as its factorization.

43591609 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 29160, while the sum is 37.

The square root of 43591609 is about 6602.3941869598. The cubic root of 43591609 is about 351.9391924275.

The spelling of 43591609 in words is "forty-three million, five hundred ninety-one thousand, six hundred nine".