3121974481921 has 3 divisors (see below), whose sum is σ = 3121976248833. Its totient is φ = 3121972715010.

The previous prime is 3121974481907. The next prime is 3121974481963. The reversal of 3121974481921 is 1291844791213.

The square root of 3121974481921 is 1766911.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 3121974481921 - 2¹¹ = 3121974479873 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3121974481621) 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 2 ways as a sum of consecutive naturals, for example, 883456 + ... + 2650366.

It is an arithmetic number, because the mean of its divisors is an integer number (1040658749611).

Almost surely, 2^{3121974481921} is an apocalyptic number.

3121974481921 is the 1766911-st square number.

3121974481921 is the 883456-th centered octagonal number.

It is an amenable number.

3121974481921 is a deficient number, since it is larger than the sum of its proper divisors (1766912).

3121974481921 is an frugal number, since it uses more digits than its factorization.

3121974481921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3533822 (or 1766911 counting only the distinct ones).

The product of its digits is 870912, while the sum is 52.

The spelling of 3121974481921 in words is "three trillion, one hundred twenty-one billion, nine hundred seventy-four million, four hundred eighty-one thousand, nine hundred twenty-one".