40039999 has 2 divisors, whose sum is σ = 40040000. Its totient is φ = 40039998.

The previous prime is 40039991. The next prime is 40040017. The reversal of 40039999 is 99993004.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 40039999 - 2³ = 40039991 is a prime.

40039999 is a modest number, since divided by 9999 gives 4003 as remainder.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (40039991) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20019999 + 20020000.

It is an arithmetic number, because the mean of its divisors is an integer number (20020000).

Almost surely, 2^40039999 is an apocalyptic number.

40039999 is a deficient number, since it is larger than the sum of its proper divisors (1).

40039999 is an equidigital number, since it uses as much as digits as its factorization.

40039999 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 78732, while the sum is 43.

The square root of 40039999 is about 6327.7167288051. The cubic root of 40039999 is about 342.1091469054.

The spelling of 40039999 in words is "forty million, thirty-nine thousand, nine hundred ninety-nine".