28660789 has 4 divisors (see below), whose sum is σ = 29130700. Its totient is φ = 28190880.

The previous prime is 28660781. The next prime is 28660799. The reversal of 28660789 is 98706682.

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 7344100 + 21316689 = 2710^2 + 4617^2 .

It is a cyclic number.

It is not a de Polignac number, because 28660789 - 2³ = 28660781 is a prime.

It is a super-2 number, since 2×28660789² = 1642881652205042, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28660781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 234864 + ... + 234985.

It is an arithmetic number, because the mean of its divisors is an integer number (7282675).

Almost surely, 2^28660789 is an apocalyptic number.

It is an amenable number.

28660789 is a deficient number, since it is larger than the sum of its proper divisors (469911).

28660789 is an equidigital number, since it uses as much as digits as its factorization.

28660789 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 469910.

The product of its (nonzero) digits is 290304, while the sum is 46.

The square root of 28660789 is about 5353.5772152833. The cubic root of 28660789 is about 306.0290921690.

It can be divided in two parts, 286 and 60789, that added together give a triangular number (61075 = T₃₄₉).

The spelling of 28660789 in words is "twenty-eight million, six hundred sixty thousand, seven hundred eighty-nine".