28489765 has 4 divisors (see below), whose sum is σ = 34187724. Its totient is φ = 22791808.

The previous prime is 28489763. The next prime is 28489771. The reversal of 28489765 is 56798482.

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 16990884 + 11498881 = 4122^2 + 3391^2 .

It is a cyclic number.

It is not a de Polignac number, because 28489765 - 2¹ = 28489763 is a prime.

It is a Smith number, since the sum of its digits (49) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28489763) 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, 2848972 + ... + 2848981.

It is an arithmetic number, because the mean of its divisors is an integer number (8546931).

Almost surely, 2^28489765 is an apocalyptic number.

It is an amenable number.

28489765 is a deficient number, since it is larger than the sum of its proper divisors (5697959).

28489765 is an equidigital number, since it uses as much as digits as its factorization.

28489765 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5697958.

The product of its digits is 967680, while the sum is 49.

The square root of 28489765 is about 5337.5804443587. The cubic root of 28489765 is about 305.4191674625.

The spelling of 28489765 in words is "twenty-eight million, four hundred eighty-nine thousand, seven hundred sixty-five".