43640987 has 4 divisors (see below), whose sum is σ = 46998000. Its totient is φ = 40283976.

The previous prime is 43640983. The next prime is 43640999. The reversal of 43640987 is 78904634.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 43640987 - 2² = 43640983 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43640983) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1678487 + ... + 1678512.

It is an arithmetic number, because the mean of its divisors is an integer number (11749500).

Almost surely, 2^43640987 is an apocalyptic number.

43640987 is a deficient number, since it is larger than the sum of its proper divisors (3357013).

43640987 is a wasteful number, since it uses less digits than its factorization.

43640987 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3357012.

The product of its (nonzero) digits is 145152, while the sum is 41.

The square root of 43640987 is about 6606.1325297030. The cubic root of 43640987 is about 352.0720275943.

The spelling of 43640987 in words is "forty-three million, six hundred forty thousand, nine hundred eighty-seven".