4039991 has 2 divisors, whose sum is σ = 4039992. Its totient is φ = 4039990.

The previous prime is 4039967. The next prime is 4040009. The reversal of 4039991 is 1999304.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 4039991 - 2¹⁰ = 4038967 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 (4039901) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2019995 + 2019996.

It is an arithmetic number, because the mean of its divisors is an integer number (2019996).

Almost surely, 2^4039991 is an apocalyptic number.

4039991 is a deficient number, since it is larger than the sum of its proper divisors (1).

4039991 is an equidigital number, since it uses as much as digits as its factorization.

4039991 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8748, while the sum is 35.

The square root of 4039991 is about 2009.9728853893. The cubic root of 4039991 is about 159.2673665678.

The spelling of 4039991 in words is "four million, thirty-nine thousand, nine hundred ninety-one".