28510561 has 4 divisors (see below), whose sum is σ = 28593072. Its totient is φ = 28428052.

The previous prime is 28510523. The next prime is 28510571. The reversal of 28510561 is 16501582.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 28510561 - 2¹⁷ = 28379489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28510571) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 40735 + ... + 41428.

It is an arithmetic number, because the mean of its divisors is an integer number (7148268).

Almost surely, 2^28510561 is an apocalyptic number.

It is an amenable number.

28510561 is a deficient number, since it is larger than the sum of its proper divisors (82511).

28510561 is an equidigital number, since it uses as much as digits as its factorization.

28510561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 82510.

The product of its (nonzero) digits is 2400, while the sum is 28.

The square root of 28510561 is about 5339.5281626751. The cubic root of 28510561 is about 305.4934625906.

The spelling of 28510561 in words is "twenty-eight million, five hundred ten thousand, five hundred sixty-one".