3991539735547 has 24 divisors (see below), whose sum is σ = 5263568898000. Its totient is φ = 2991923355456.

The previous prime is 3991539735503. The next prime is 3991539735551. The reversal of 3991539735547 is 7455379351993.

It is not a de Polignac number, because 3991539735547 - 2¹⁵ = 3991539702779 is a prime.

It is a super-2 number, since 2×3991539735547² (a number of 26 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (3991539735947) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 164886672 + ... + 164910877.

It is an arithmetic number, because the mean of its divisors is an integer number (219315370750).

Almost surely, 2^{3991539735547} is an apocalyptic number.

3991539735547 is a deficient number, since it is larger than the sum of its proper divisors (1272029162453).

3991539735547 is a wasteful number, since it uses less digits than its factorization.

3991539735547 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 329797595 (or 329797588 counting only the distinct ones).

The product of its digits is 482233500, while the sum is 70.

The spelling of 3991539735547 in words is "three trillion, nine hundred ninety-one billion, five hundred thirty-nine million, seven hundred thirty-five thousand, five hundred forty-seven".