28571689 has 4 divisors (see below), whose sum is σ = 28963156. Its totient is φ = 28180224.

The previous prime is 28571663. The next prime is 28571771. The reversal of 28571689 is 98617582.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 8456464 + 20115225 = 2908^2 + 4485^2 .

It is a cyclic number.

It is not a de Polignac number, because 28571689 - 2⁵ = 28571657 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28571639) 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, 195624 + ... + 195769.

It is an arithmetic number, because the mean of its divisors is an integer number (7240789).

Almost surely, 2^28571689 is an apocalyptic number.

It is an amenable number.

28571689 is a deficient number, since it is larger than the sum of its proper divisors (391467).

28571689 is an equidigital number, since it uses as much as digits as its factorization.

28571689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391466.

The product of its digits is 241920, while the sum is 46.

The square root of 28571689 is about 5345.2491990552. The cubic root of 28571689 is about 305.7116375811.

The spelling of 28571689 in words is "twenty-eight million, five hundred seventy-one thousand, six hundred eighty-nine".