28645562721 has 16 divisors (see below), whose sum is σ = 38252672640. Its totient is φ = 19067775360.

The previous prime is 28645562713. The next prime is 28645562749. The reversal of 28645562721 is 12726554682.

It is not a de Polignac number, because 28645562721 - 2³ = 28645562713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28645562821) 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 15 ways as a sum of consecutive naturals, for example, 7413436 + ... + 7417298.

It is an arithmetic number, because the mean of its divisors is an integer number (2390792040).

Almost surely, 2^28645562721 is an apocalyptic number.

It is an amenable number.

28645562721 is a deficient number, since it is larger than the sum of its proper divisors (9607109919).

28645562721 is a wasteful number, since it uses less digits than its factorization.

28645562721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7016.

The product of its digits is 1612800, while the sum is 48.

The spelling of 28645562721 in words is "twenty-eight billion, six hundred forty-five million, five hundred sixty-two thousand, seven hundred twenty-one".