28557443321 has 4 divisors (see below), whose sum is σ = 31153574544. Its totient is φ = 25961312100.

The previous prime is 28557443303. The next prime is 28557443329. The reversal of 28557443321 is 12334475582.

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 not a de Polignac number, because 28557443321 - 2³⁴ = 11377574137 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28557443329) 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, 1298065595 + ... + 1298065616.

It is an arithmetic number, because the mean of its divisors is an integer number (7788393636).

Almost surely, 2^28557443321 is an apocalyptic number.

It is an amenable number.

28557443321 is a deficient number, since it is larger than the sum of its proper divisors (2596131223).

28557443321 is a wasteful number, since it uses less digits than its factorization.

28557443321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2596131222.

The product of its digits is 806400, while the sum is 44.

The spelling of 28557443321 in words is "twenty-eight billion, five hundred fifty-seven million, four hundred forty-three thousand, three hundred twenty-one".