3909131685 has 20 divisors (see below), whose sum is σ = 7007481228. Its totient is φ = 2084870016.

The previous prime is 3909131663. The next prime is 3909131693. The reversal of 3909131685 is 5861319093.

It can be written as a sum of positive squares in 2 ways, for example, as 2402372196 + 1506759489 = 49014^2 + 38817^2 .

It is not a de Polignac number, because 3909131685 - 2⁷ = 3909131557 is a prime.

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 3909131685.

It is a congruent number.

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, 4825684 + ... + 4826493.

Almost surely, 2^3909131685 is an apocalyptic number.

It is an amenable number.

3909131685 is a deficient number, since it is larger than the sum of its proper divisors (3098349543).

3909131685 is an equidigital number, since it uses as much as digits as its factorization.

3909131685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9652194 (or 9652185 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 45.

The square root of 3909131685 is about 62523.0492298640. The cubic root of 3909131685 is about 1575.2884913717.

The spelling of 3909131685 in words is "three billion, nine hundred nine million, one hundred thirty-one thousand, six hundred eighty-five".