40043399 has 4 divisors (see below), whose sum is σ = 43683720. Its totient is φ = 36403080.

The previous prime is 40043383. The next prime is 40043401. The reversal of 40043399 is 99334004.

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 40043399 - 2⁴ = 40043383 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40043309) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1820144 + ... + 1820165.

It is an arithmetic number, because the mean of its divisors is an integer number (10920930).

Almost surely, 2^40043399 is an apocalyptic number.

40043399 is a deficient number, since it is larger than the sum of its proper divisors (3640321).

40043399 is a wasteful number, since it uses less digits than its factorization.

40043399 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3640320.

The product of its (nonzero) digits is 11664, while the sum is 32.

The square root of 40043399 is about 6327.9853824104. The cubic root of 40043399 is about 342.1188300406.

Subtracting 40043399 from its reverse (99334004), we obtain a triangular number (59290605 = T₁₀₈₈₉).

The spelling of 40043399 in words is "forty million, forty-three thousand, three hundred ninety-nine".