43990399 has 2 divisors, whose sum is σ = 43990400. Its totient is φ = 43990398.

The previous prime is 43990381. The next prime is 43990423. The reversal of 43990399 is 99309934.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 43990399 - 2⁹ = 43989887 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (43990799) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 21995199 + 21995200.

It is an arithmetic number, because the mean of its divisors is an integer number (21995200).

Almost surely, 2^43990399 is an apocalyptic number.

43990399 is a deficient number, since it is larger than the sum of its proper divisors (1).

43990399 is an equidigital number, since it uses as much as digits as its factorization.

43990399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 236196, while the sum is 46.

The square root of 43990399 is about 6632.5258386229. The cubic root of 43990399 is about 353.0091537296.

The spelling of 43990399 in words is "forty-three million, nine hundred ninety thousand, three hundred ninety-nine".