3991607 has 2 divisors, whose sum is σ = 3991608. Its totient is φ = 3991606.

The previous prime is 3991601. The next prime is 3991609. The reversal of 3991607 is 7061993.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 3991607 - 2⁶ = 3991543 is a prime.

Together with 3991609, it forms a pair of twin primes.

It is a Chen prime.

It is equal to p₂₈₂₅₉₉ and since 3991607 and 282599 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3991601) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a good prime.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1995803 + 1995804.

It is an arithmetic number, because the mean of its divisors is an integer number (1995804).

Almost surely, 2^3991607 is an apocalyptic number.

3991607 is a deficient number, since it is larger than the sum of its proper divisors (1).

3991607 is an equidigital number, since it uses as much as digits as its factorization.

3991607 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 10206, while the sum is 35.

The square root of 3991607 is about 1997.9006481805. The cubic root of 3991607 is about 158.6290019779.

The spelling of 3991607 in words is "three million, nine hundred ninety-one thousand, six hundred seven".