3924187375681 has 4 divisors (see below), whose sum is σ = 3924404235652. Its totient is φ = 3923970515712.

The previous prime is 3924187375609. The next prime is 3924187375741. The reversal of 3924187375681 is 1865737814293.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1020857640625 + 2903329735056 = 1010375^2 + 1703916^2 .

It is a cyclic number.

It is not a de Polignac number, because 3924187375681 - 2⁹ = 3924187375169 is a prime.

It is a super-2 number, since 2×3924187375681² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3924187375181) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 108402840 + ... + 108439033.

It is an arithmetic number, because the mean of its divisors is an integer number (981101058913).

Almost surely, 2^{3924187375681} is an apocalyptic number.

It is an amenable number.

3924187375681 is a deficient number, since it is larger than the sum of its proper divisors (216859971).

3924187375681 is a wasteful number, since it uses less digits than its factorization.

3924187375681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 216859970.

The product of its digits is 60963840, while the sum is 64.

The spelling of 3924187375681 in words is "three trillion, nine hundred twenty-four billion, one hundred eighty-seven million, three hundred seventy-five thousand, six hundred eighty-one".