43640661 has 8 divisors (see below), whose sum is σ = 58573504. Its totient is φ = 28900800.

The previous prime is 43640633. The next prime is 43640671. The reversal of 43640661 is 16604634.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 43640661 - 2⁷ = 43640533 is a prime.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (43640671) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 47716 + ... + 48621.

It is an arithmetic number, because the mean of its divisors is an integer number (7321688).

Almost surely, 2^43640661 is an apocalyptic number.

It is an amenable number.

43640661 is a deficient number, since it is larger than the sum of its proper divisors (14932843).

43640661 is a wasteful number, since it uses less digits than its factorization.

43640661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96491.

The product of its (nonzero) digits is 10368, while the sum is 30.

The square root of 43640661 is about 6606.1078556136. The cubic root of 43640661 is about 352.0711509278.

The spelling of 43640661 in words is "forty-three million, six hundred forty thousand, six hundred sixty-one".