2109087319681 has 4 divisors (see below), whose sum is σ = 2114741709652. Its totient is φ = 2103432929712.

The previous prime is 2109087319679. The next prime is 2109087319693. The reversal of 2109087319681 is 1869137809012.

It is a happy number.

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 379651913281 + 1729435406400 = 616159^2 + 1315080^2 .

It is a cyclic number.

It is not a de Polignac number, because 2109087319681 - 2¹ = 2109087319679 is a prime.

It is a super-2 number, since 2×2109087319681² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2109087319181) 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, 2827194426 + ... + 2827195171.

It is an arithmetic number, because the mean of its divisors is an integer number (528685427413).

Almost surely, 2^{2109087319681} is an apocalyptic number.

It is an amenable number.

2109087319681 is a deficient number, since it is larger than the sum of its proper divisors (5654389971).

2109087319681 is an equidigital number, since it uses as much as digits as its factorization.

2109087319681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5654389970.

The product of its (nonzero) digits is 1306368, while the sum is 55.

The spelling of 2109087319681 in words is "two trillion, one hundred nine billion, eighty-seven million, three hundred nineteen thousand, six hundred eighty-one".