3121113415681 has 4 divisors (see below), whose sum is σ = 3163868394052. Its totient is φ = 3078358437312.

The previous prime is 3121113415657. The next prime is 3121113415687. The reversal of 3121113415681 is 1865143111213.

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 2156316033600 + 964797382081 = 1468440^2 + 982241^2 .

It is a cyclic number.

It is not a de Polignac number, because 3121113415681 - 2²¹ = 3121111318529 is a prime.

It is a super-2 number, since 2×3121113415681² (a number of 26 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 3121113415681.

It is not an unprimeable number, because it can be changed into a prime (3121113415687) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21377489076 + ... + 21377489221.

It is an arithmetic number, because the mean of its divisors is an integer number (790967098513).

Almost surely, 2^{3121113415681} is an apocalyptic number.

It is an amenable number.

3121113415681 is a deficient number, since it is larger than the sum of its proper divisors (42754978371).

3121113415681 is an equidigital number, since it uses as much as digits as its factorization.

3121113415681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42754978370.

The product of its digits is 17280, while the sum is 37.

Adding to 3121113415681 its reverse (1865143111213), we get a palindrome (4986256526894).

The spelling of 3121113415681 in words is "three trillion, one hundred twenty-one billion, one hundred thirteen million, four hundred fifteen thousand, six hundred eighty-one".