43664018 has 4 divisors (see below), whose sum is σ = 65496030. Its totient is φ = 21832008.

The previous prime is 43664009. The next prime is 43664063. The reversal of 43664018 is 81046634.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 81046634 = 2 ⋅40523317.

It can be written as a sum of positive squares in only one way, i.e., 41434969 + 2229049 = 6437^2 + 1493^2 .

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10916003 + ... + 10916006.

Almost surely, 2^43664018 is an apocalyptic number.

43664018 is a deficient number, since it is larger than the sum of its proper divisors (21832012).

43664018 is a wasteful number, since it uses less digits than its factorization.

43664018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 21832011.

The product of its (nonzero) digits is 13824, while the sum is 32.

The square root of 43664018 is about 6607.8754528214. The cubic root of 43664018 is about 352.1339506124.

The spelling of 43664018 in words is "forty-three million, six hundred sixty-four thousand, eighteen".