28265509 has 16 divisors (see below), whose sum is σ = 30841776. Its totient is φ = 25804800.

The previous prime is 28265507. The next prime is 28265533. The reversal of 28265509 is 90556282.

It is a happy number.

It can be written as a sum of positive squares in 8 ways, for example, as 228484 + 28037025 = 478^2 + 5295^2 .

It is a cyclic number.

It is not a de Polignac number, because 28265509 - 2¹ = 28265507 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28265507) 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 15 ways as a sum of consecutive naturals, for example, 100449 + ... + 100729.

It is an arithmetic number, because the mean of its divisors is an integer number (1927611).

Almost surely, 2^28265509 is an apocalyptic number.

It is an amenable number.

28265509 is a deficient number, since it is larger than the sum of its proper divisors (2576267).

28265509 is a wasteful number, since it uses less digits than its factorization.

28265509 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 456.

The product of its (nonzero) digits is 43200, while the sum is 37.

The square root of 28265509 is about 5316.5316701775. The cubic root of 28265509 is about 304.6156908257.

The spelling of 28265509 in words is "twenty-eight million, two hundred sixty-five thousand, five hundred nine".