3872787646861 has 12 divisors (see below), whose sum is σ = 4505211503100. Its totient is φ = 3319435008960.

The previous prime is 3872787646859. The next prime is 3872787646879. The reversal of 3872787646861 is 1686467872783.

It can be written as a sum of positive squares in 2 ways, for example, as 2682356084100 + 1190431562761 = 1637790^2 + 1091069^2 .

It is not a de Polignac number, because 3872787646861 - 2¹ = 3872787646859 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (3872787646891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 557271 + ... + 2838331.

It is an arithmetic number, because the mean of its divisors is an integer number (375434291925).

Almost surely, 2^{3872787646861} is an apocalyptic number.

It is an amenable number.

3872787646861 is a deficient number, since it is larger than the sum of its proper divisors (632423856239).

3872787646861 is a wasteful number, since it uses less digits than its factorization.

3872787646861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2315724 (or 2315717 counting only the distinct ones).

The product of its digits is 910393344, while the sum is 73.

The spelling of 3872787646861 in words is "three trillion, eight hundred seventy-two billion, seven hundred eighty-seven million, six hundred forty-six thousand, eight hundred sixty-one".