857728369 has 3 divisors (see below), whose sum is σ = 857757657. Its totient is φ = 857699082.

The previous prime is 857728363. The next prime is 857728379. The reversal of 857728369 is 963827758.

The square root of 857728369 is 29287.

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.

It is not a de Polignac number, because 857728369 - 2⁵ = 857728337 is a prime.

It is a super-2 number, since 2×857728369² = 1471395909974800322, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (857728363) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 14644 + ... + 43930.

It is an arithmetic number, because the mean of its divisors is an integer number (285919219).

Almost surely, 2^857728369 is an apocalyptic number.

857728369 is the 29287-th square number.

857728369 is the 14644-th centered octagonal number.

It is an amenable number.

857728369 is a deficient number, since it is larger than the sum of its proper divisors (29288).

857728369 is an frugal number, since it uses more digits than its factorization.

857728369 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58574 (or 29287 counting only the distinct ones).

The product of its digits is 5080320, while the sum is 55.

The cubic root of 857728369 is about 950.1304969396.

The spelling of 857728369 in words is "eight hundred fifty-seven million, seven hundred twenty-eight thousand, three hundred sixty-nine".