28652509 has 4 divisors (see below), whose sum is σ = 28683900. Its totient is φ = 28621120.

The previous prime is 28652473. The next prime is 28652527. The reversal of 28652509 is 90525682.

It is a happy number.

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 9903609 + 18748900 = 3147^2 + 4330^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28652509 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 (28652579) 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, 14284 + ... + 16165.

It is an arithmetic number, because the mean of its divisors is an integer number (7170975).

Almost surely, 2^28652509 is an apocalyptic number.

It is an amenable number.

28652509 is a deficient number, since it is larger than the sum of its proper divisors (31391).

28652509 is an equidigital number, since it uses as much as digits as its factorization.

28652509 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31390.

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

The square root of 28652509 is about 5352.8038447154. The cubic root of 28652509 is about 305.9996190919. Note that the first 3 decimals are identical.

It can be divided in two parts, 28652 and 509, that added together give a triangular number (29161 = T₂₄₁).

The spelling of 28652509 in words is "twenty-eight million, six hundred fifty-two thousand, five hundred nine".