28872466561 has 3 divisors (see below), whose sum is σ = 28872636481. Its totient is φ = 28872296642.

The previous prime is 28872466537. The next prime is 28872466583. The reversal of 28872466561 is 16566427882.

The square root of 28872466561 is 169919.

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, and also an emirpimes, since its reverse is a distinct semiprime: 16566427882 = 2 ⋅8283213941.

It is not a de Polignac number, because 28872466561 - 2¹³ = 28872458369 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28872466261) 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, 84960 + ... + 254878.

Almost surely, 2^28872466561 is an apocalyptic number.

28872466561 is the 169919-th square number.

28872466561 is the 84960-th centered octagonal number.

It is an amenable number.

28872466561 is a deficient number, since it is larger than the sum of its proper divisors (169920).

28872466561 is an frugal number, since it uses more digits than its factorization.

28872466561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 339838 (or 169919 counting only the distinct ones).

The product of its digits is 7741440, while the sum is 55.

The spelling of 28872466561 in words is "twenty-eight billion, eight hundred seventy-two million, four hundred sixty-six thousand, five hundred sixty-one".