3991914989 has 12 divisors (see below), whose sum is σ = 4139253300. Its totient is φ = 3849659520.

The previous prime is 3991914977. The next prime is 3991915001. The reversal of 3991914989 is 9894191993.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (3991914977) and next prime (3991915001).

It can be written as a sum of positive squares in 6 ways, for example, as 562875625 + 3429039364 = 23725^2 + 58558^2 .

It is a de Polignac number, because none of the positive numbers 2^k-3991914989 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3991914389) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 856337 + ... + 860985.

It is an arithmetic number, because the mean of its divisors is an integer number (344937775).

Almost surely, 2^3991914989 is an apocalyptic number.

It is an amenable number.

3991914989 is a deficient number, since it is larger than the sum of its proper divisors (147338311).

3991914989 is a wasteful number, since it uses less digits than its factorization.

3991914989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5728 (or 5699 counting only the distinct ones).

The product of its digits is 5668704, while the sum is 62.

The square root of 3991914989 is about 63181.6032480975. The cubic root of 3991914989 is about 1586.3308176588.

The spelling of 3991914989 in words is "three billion, nine hundred ninety-one million, nine hundred fourteen thousand, nine hundred eighty-nine".