28557065 has 4 divisors (see below), whose sum is σ = 34268484. Its totient is φ = 22845648.

The previous prime is 28557047. The next prime is 28557077. The reversal of 28557065 is 56075582.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56075582 = 2 ⋅28037791.

It can be written as a sum of positive squares in 2 ways, for example, as 5555449 + 23001616 = 2357^2 + 4796^2 .

It is a cyclic number.

It is not a de Polignac number, because 28557065 - 2⁸ = 28556809 is a prime.

It is a super-2 number, since 2×28557065² = 1631011922828450, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2855702 + ... + 2855711.

It is an arithmetic number, because the mean of its divisors is an integer number (8567121).

Almost surely, 2^28557065 is an apocalyptic number.

It is an amenable number.

28557065 is a deficient number, since it is larger than the sum of its proper divisors (5711419).

28557065 is an equidigital number, since it uses as much as digits as its factorization.

28557065 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5711418.

The product of its (nonzero) digits is 84000, while the sum is 38.

The square root of 28557065 is about 5343.8810802637. The cubic root of 28557065 is about 305.6594706737.

The spelling of 28557065 in words is "twenty-eight million, five hundred fifty-seven thousand, sixty-five".