3991528085291 has 8 divisors (see below), whose sum is σ = 4228012403424. Its totient is φ = 3755231383680.

The previous prime is 3991528085213. The next prime is 3991528085327. The reversal of 3991528085291 is 1925808251993.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3991528085291 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3991528085491) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 46860320 + ... + 46945421.

It is an arithmetic number, because the mean of its divisors is an integer number (528501550428).

Almost surely, 2^{3991528085291} is an apocalyptic number.

3991528085291 is a deficient number, since it is larger than the sum of its proper divisors (236484318133).

3991528085291 is a wasteful number, since it uses less digits than its factorization.

3991528085291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 93808261.

The product of its (nonzero) digits is 13996800, while the sum is 62.

The spelling of 3991528085291 in words is "three trillion, nine hundred ninety-one billion, five hundred twenty-eight million, eighty-five thousand, two hundred ninety-one".