3991607663 has 2 divisors, whose sum is σ = 3991607664. Its totient is φ = 3991607662.

The previous prime is 3991607639. The next prime is 3991607671. The reversal of 3991607663 is 3667061993.

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-3991607663 is a prime.

It is a super-3 number, since 3×3991607663³ (a number of 30 digits) contains 333 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3991609663) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1995803831 + 1995803832.

It is an arithmetic number, because the mean of its divisors is an integer number (1995803832).

Almost surely, 2^3991607663 is an apocalyptic number.

3991607663 is a deficient number, since it is larger than the sum of its proper divisors (1).

3991607663 is an equidigital number, since it uses as much as digits as its factorization.

3991607663 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1102248, while the sum is 50.

The square root of 3991607663 is about 63179.1711167533. The cubic root of 3991607663 is about 1586.2901076054.

The spelling of 3991607663 in words is "three billion, nine hundred ninety-one million, six hundred seven thousand, six hundred sixty-three".