28628828321 has 4 divisors (see below), whose sum is σ = 29552338944. Its totient is φ = 27705317700.

The previous prime is 28628828287. The next prime is 28628828323. The reversal of 28628828321 is 12382882682.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28628828321 is a prime.

It is a super-2 number, since 2×28628828321² (a number of 22 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 28628828321.

It is not an unprimeable number, because it can be changed into a prime (28628828323) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 461755265 + ... + 461755326.

It is an arithmetic number, because the mean of its divisors is an integer number (7388084736).

Almost surely, 2^28628828321 is an apocalyptic number.

It is an amenable number.

28628828321 is a deficient number, since it is larger than the sum of its proper divisors (923510623).

28628828321 is an equidigital number, since it uses as much as digits as its factorization.

28628828321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923510622.

The product of its digits is 1179648, while the sum is 50.

The spelling of 28628828321 in words is "twenty-eight billion, six hundred twenty-eight million, eight hundred twenty-eight thousand, three hundred twenty-one".