3985398749691 has 6 divisors (see below), whose sum is σ = 5756687082900. Its totient is φ = 2656932499788.

The previous prime is 3985398749669. The next prime is 3985398749723. The reversal of 3985398749691 is 1969478935893.

3985398749691 is a `hidden beast` number, since 3 + 9 + 8 + 5 + 39 + 8 + 7 + 496 + 91 = 666.

It is not a de Polignac number, because 3985398749691 - 2⁶ = 3985398749627 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 3985398749691.

It is not an unprimeable number, because it can be changed into a prime (3985398749611) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 221411041641 + ... + 221411041658.

It is an arithmetic number, because the mean of its divisors is an integer number (959447847150).

Almost surely, 2^{3985398749691} is an apocalyptic number.

3985398749691 is a deficient number, since it is larger than the sum of its proper divisors (1771288333209).

3985398749691 is a wasteful number, since it uses less digits than its factorization.

3985398749691 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 442822083305 (or 442822083302 counting only the distinct ones).

The product of its digits is 3174474240, while the sum is 81.

The spelling of 3985398749691 in words is "three trillion, nine hundred eighty-five billion, three hundred ninety-eight million, seven hundred forty-nine thousand, six hundred ninety-one".