43990565 has 4 divisors (see below), whose sum is σ = 52788684. Its totient is φ = 35192448.

The previous prime is 43990553. The next prime is 43990601. The reversal of 43990565 is 56509934.

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 8014561 + 35976004 = 2831^2 + 5998^2 .

It is a cyclic number.

It is not a de Polignac number, because 43990565 - 2⁴ = 43990549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4399052 + ... + 4399061.

It is an arithmetic number, because the mean of its divisors is an integer number (13197171).

Almost surely, 2^43990565 is an apocalyptic number.

It is an amenable number.

43990565 is a deficient number, since it is larger than the sum of its proper divisors (8798119).

43990565 is an equidigital number, since it uses as much as digits as its factorization.

43990565 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8798118.

The product of its (nonzero) digits is 145800, while the sum is 41.

The square root of 43990565 is about 6632.5383526973. The cubic root of 43990565 is about 353.0095977617.

The spelling of 43990565 in words is "forty-three million, nine hundred ninety thousand, five hundred sixty-five".