28658561 has 4 divisors (see below), whose sum is σ = 28760112. Its totient is φ = 28557012.

The previous prime is 28658557. The next prime is 28658563. The reversal of 28658561 is 16585682.

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 28658561 - 2² = 28658557 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (28658563) 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, 50351 + ... + 50916.

It is an arithmetic number, because the mean of its divisors is an integer number (7190028).

Almost surely, 2^28658561 is an apocalyptic number.

It is an amenable number.

28658561 is a deficient number, since it is larger than the sum of its proper divisors (101551).

28658561 is a wasteful number, since it uses less digits than its factorization.

28658561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101550.

The product of its digits is 115200, while the sum is 41.

The square root of 28658561 is about 5353.3691260738. The cubic root of 28658561 is about 306.0211620491.

The spelling of 28658561 in words is "twenty-eight million, six hundred fifty-eight thousand, five hundred sixty-one".