3172278025921 has 3 divisors (see below), whose sum is σ = 3172279807011. Its totient is φ = 3172276244832.

The previous prime is 3172278025901. The next prime is 3172278025927. The reversal of 3172278025921 is 1295208722713.

The square root of 3172278025921 is 1781089.

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 can be written as a sum of positive squares in only one way, i.e., 2691696328321 + 480581697600 = 1640639^2 + 693240^2 .

It is not a de Polignac number, because 3172278025921 - 2³⁷ = 3034839072449 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3172278025927) 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 2 ways as a sum of consecutive naturals, for example, 890545 + ... + 2671633.

It is an arithmetic number, because the mean of its divisors is an integer number (1057426602337).

Almost surely, 2^{3172278025921} is an apocalyptic number.

3172278025921 is the 1781089-th square number.

3172278025921 is the 890545-th centered octagonal number.

It is an amenable number.

3172278025921 is a deficient number, since it is larger than the sum of its proper divisors (1781090).

3172278025921 is an frugal number, since it uses more digits than its factorization.

3172278025921 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3562178 (or 1781089 counting only the distinct ones).

The product of its (nonzero) digits is 846720, while the sum is 49.

Multiplying 3172278025921 by its sum of digits (49), we get a square (155441623270129 = 12467623²).

The spelling of 3172278025921 in words is "three trillion, one hundred seventy-two billion, two hundred seventy-eight million, twenty-five thousand, nine hundred twenty-one".