43643645 has 16 divisors (see below), whose sum is σ = 53751600. Its totient is φ = 34005504.

The previous prime is 43643623. The next prime is 43643647. The reversal of 43643645 is 54634634.

It can be written as a sum of positive squares in 8 ways, for example, as 1315609 + 42328036 = 1147^2 + 6506^2 .

It is a cyclic number.

It is not a de Polignac number, because 43643645 - 2¹² = 43639549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43643647) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41081 + ... + 42129.

It is an arithmetic number, because the mean of its divisors is an integer number (3359475).

Almost surely, 2^43643645 is an apocalyptic number.

It is an amenable number.

43643645 is a deficient number, since it is larger than the sum of its proper divisors (10107955).

43643645 is a wasteful number, since it uses less digits than its factorization.

43643645 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1264.

The product of its digits is 103680, while the sum is 35.

The square root of 43643645 is about 6606.3337033486. Note that the first 3 decimals coincide. The cubic root of 43643645 is about 352.0791752210.

The spelling of 43643645 in words is "forty-three million, six hundred forty-three thousand, six hundred forty-five".