43993681 has 8 divisors (see below), whose sum is σ = 45865728. Its totient is φ = 42150000.

The previous prime is 43993673. The next prime is 43993717. The reversal of 43993681 is 18639934.

43993681 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is a cyclic number.

It is not a de Polignac number, because 43993681 - 2³ = 43993673 is a prime.

It is a super-2 number, since 2×43993681² = 3870887935859522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (43991681) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3895 + ... + 10156.

It is an arithmetic number, because the mean of its divisors is an integer number (5733216).

Almost surely, 2^43993681 is an apocalyptic number.

It is an amenable number.

43993681 is a deficient number, since it is larger than the sum of its proper divisors (1872047).

43993681 is a wasteful number, since it uses less digits than its factorization.

43993681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14183.

The product of its digits is 139968, while the sum is 43.

The square root of 43993681 is about 6632.7732510617. The cubic root of 43993681 is about 353.0179325181.

The spelling of 43993681 in words is "forty-three million, nine hundred ninety-three thousand, six hundred eighty-one".