28257570665 has 8 divisors (see below), whose sum is σ = 34081213320. Its totient is φ = 22491304192.

The previous prime is 28257570641. The next prime is 28257570673. The reversal of 28257570665 is 56607575282.

It can be written as a sum of positive squares in 4 ways, for example, as 3770328409 + 24487242256 = 61403^2 + 156484^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28257570665 - 2²⁰ = 28256522089 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14342960 + ... + 14344929.

It is an arithmetic number, because the mean of its divisors is an integer number (4260151665).

Almost surely, 2^28257570665 is an apocalyptic number.

It is an amenable number.

28257570665 is a deficient number, since it is larger than the sum of its proper divisors (5823642655).

28257570665 is a wasteful number, since it uses less digits than its factorization.

28257570665 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28688091.

The product of its (nonzero) digits is 7056000, while the sum is 53.

The spelling of 28257570665 in words is "twenty-eight billion, two hundred fifty-seven million, five hundred seventy thousand, six hundred sixty-five".