40001999 has 2 divisors, whose sum is σ = 40002000. Its totient is φ = 40001998.

The previous prime is 40001987. The next prime is 40002023. The reversal of 40001999 is 99910004.

40001999 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 40001999 - 2⁸ = 40001743 is a prime.

It is a Sophie Germain prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40001939) 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 as a sum of consecutive naturals, namely, 20000999 + 20001000.

It is an arithmetic number, because the mean of its divisors is an integer number (20001000).

Almost surely, 2^40001999 is an apocalyptic number.

40001999 is a deficient number, since it is larger than the sum of its proper divisors (1).

40001999 is an equidigital number, since it uses as much as digits as its factorization.

40001999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 40001999 is about 6324.7133531884. The cubic root of 40001999 is about 342.0008863103. Note that the first 3 decimals are identical.

The spelling of 40001999 in words is "forty million, one thousand, nine hundred ninety-nine".