40439939 has 2 divisors, whose sum is σ = 40439940. Its totient is φ = 40439938.

The previous prime is 40439879. The next prime is 40439947. The reversal of 40439939 is 93993404.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-40439939 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a junction number, because it is equal to n+sod(n) for n = 40439896 and 40439905.

It is not a weakly prime, because it can be changed into another prime (40439969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 20219969 + 20219970.

It is an arithmetic number, because the mean of its divisors is an integer number (20219970).

Almost surely, 2^40439939 is an apocalyptic number.

40439939 is a deficient number, since it is larger than the sum of its proper divisors (1).

40439939 is an equidigital number, since it uses as much as digits as its factorization.

40439939 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 104976, while the sum is 41.

The square root of 40439939 is about 6359.2404420654. The cubic root of 40439939 is about 343.2444290707.

The spelling of 40439939 in words is "forty million, four hundred thirty-nine thousand, nine hundred thirty-nine".