40399999 has 4 divisors (see below), whose sum is σ = 40792336. Its totient is φ = 40007664.

The previous prime is 40399981. The next prime is 40400011. The reversal of 40399999 is 99999304.

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 40399999 - 2⁹ = 40399487 is a prime.

It is a Duffinian number.

40399999 is a modest number, since divided by 9999 gives 4039 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (40399969) 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, 196014 + ... + 196219.

It is an arithmetic number, because the mean of its divisors is an integer number (10198084).

Almost surely, 2^40399999 is an apocalyptic number.

40399999 is a deficient number, since it is larger than the sum of its proper divisors (392337).

40399999 is a wasteful number, since it uses less digits than its factorization.

40399999 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 392336.

The product of its (nonzero) digits is 708588, while the sum is 52.

The square root of 40399999 is about 6356.0993541637. The cubic root of 40399999 is about 343.1313914932.

The spelling of 40399999 in words is "forty million, three hundred ninety-nine thousand, nine hundred ninety-nine".