28509655 has 4 divisors (see below), whose sum is σ = 34211592. Its totient is φ = 22807720.

The previous prime is 28509619. The next prime is 28509659. The reversal of 28509655 is 55690582.

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

It is not a de Polignac number, because 28509655 - 2¹⁹ = 27985367 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 (28509659) 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, 2850961 + ... + 2850970.

It is an arithmetic number, because the mean of its divisors is an integer number (8552898).

Almost surely, 2^28509655 is an apocalyptic number.

28509655 is a deficient number, since it is larger than the sum of its proper divisors (5701937).

28509655 is an equidigital number, since it uses as much as digits as its factorization.

28509655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5701936.

The product of its (nonzero) digits is 108000, while the sum is 40.

The square root of 28509655 is about 5339.4433230441. The cubic root of 28509655 is about 305.4902265966.

The spelling of 28509655 in words is "twenty-eight million, five hundred nine thousand, six hundred fifty-five".