43728561 has 12 divisors (see below), whose sum is σ = 64871092. Its totient is φ = 28364256.

The previous prime is 43728541. The next prime is 43728563. The reversal of 43728561 is 16582734.

It can be written as a sum of positive squares in 2 ways, for example, as 25401600 + 18326961 = 5040^2 + 4281^2 .

It is not a de Polignac number, because 43728561 - 2⁹ = 43728049 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43728563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 65326 + ... + 65991.

Almost surely, 2^43728561 is an apocalyptic number.

It is an amenable number.

43728561 is a deficient number, since it is larger than the sum of its proper divisors (21142531).

43728561 is a wasteful number, since it uses less digits than its factorization.

43728561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 131360 (or 131357 counting only the distinct ones).

The product of its digits is 40320, while the sum is 36.

The square root of 43728561 is about 6612.7574430036. The cubic root of 43728561 is about 352.3073702324.

The spelling of 43728561 in words is "forty-three million, seven hundred twenty-eight thousand, five hundred sixty-one".