3999971 has 2 divisors, whose sum is σ = 3999972. Its totient is φ = 3999970.

The previous prime is 3999949. The next prime is 4000037. The reversal of 3999971 is 1799993.

It is a happy number.

3999971 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 3999971 - 2¹⁴ = 3983587 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (3999901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1999985 + 1999986.

It is an arithmetic number, because the mean of its divisors is an integer number (1999986).

Almost surely, 2^3999971 is an apocalyptic number.

3999971 is a deficient number, since it is larger than the sum of its proper divisors (1).

3999971 is an equidigital number, since it uses as much as digits as its factorization.

3999971 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 137781, while the sum is 47.

The square root of 3999971 is about 1999.9927499869. The cubic root of 3999971 is about 158.7397215740.

The spelling of 3999971 in words is "three million, nine hundred ninety-nine thousand, nine hundred seventy-one".