3991539742020 has 60 divisors (see below), whose sum is σ = 12521608010604. Its totient is φ = 1064410597440.

The previous prime is 3991539741991. The next prime is 3991539742067. The reversal of 3991539742020 is 202479351993.

3991539742020 is a `hidden beast` number, since 39 + 9 + 1 + 539 + 74 + 2 + 0 + 2 + 0 = 666.

3991539742020 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 2453934782016 + 1537604960004 = 1566504^2 + 1240002^2 .

It is a tau number, because it is divible by the number of its divisors (60).

It is a Harshad number since it is a multiple of its sum of digits (54).

It is an unprimeable number.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 1231955091 + ... + 1231958330.

Almost surely, 2^{3991539742020} is an apocalyptic number.

3991539742020 is a gapful number since it is divisible by the number (30) formed by its first and last digit.

It is an amenable number.

3991539742020 is an abundant number, since it is smaller than the sum of its proper divisors (8530068268584).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

3991539742020 is a wasteful number, since it uses less digits than its factorization.

3991539742020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2463913442 (or 2463913431 counting only the distinct ones).

The product of its (nonzero) digits is 3674160, while the sum is 54.

The spelling of 3991539742020 in words is "three trillion, nine hundred ninety-one billion, five hundred thirty-nine million, seven hundred forty-two thousand, twenty".