3991527989 has 2 divisors, whose sum is σ = 3991527990. Its totient is φ = 3991527988.

The previous prime is 3991527983. The next prime is 3991528043. The reversal of 3991527989 is 9897251993.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 3960814225 + 30713764 = 62935^2 + 5542^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3991527989 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (3991527983) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1995763994 + 1995763995.

It is an arithmetic number, because the mean of its divisors is an integer number (1995763995).

Almost surely, 2^3991527989 is an apocalyptic number.

It is an amenable number.

3991527989 is a deficient number, since it is larger than the sum of its proper divisors (1).

3991527989 is an equidigital number, since it uses as much as digits as its factorization.

3991527989 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 11022480, while the sum is 62.

The square root of 3991527989 is about 63178.5405735207. The cubic root of 3991527989 is about 1586.2795532182.

The spelling of 3991527989 in words is "three billion, nine hundred ninety-one million, five hundred twenty-seven thousand, nine hundred eighty-nine".