28576391 has 4 divisors (see below), whose sum is σ = 28615800. Its totient is φ = 28536984.

The previous prime is 28576369. The next prime is 28576393. The reversal of 28576391 is 19367582.

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

It is a cyclic number.

It is not a de Polignac number, because 28576391 - 2²² = 24382087 is a prime.

It is a super-2 number, since 2×28576391² = 1633220245169762, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28576393) 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, 18596 + ... + 20073.

It is an arithmetic number, because the mean of its divisors is an integer number (7153950).

Almost surely, 2^28576391 is an apocalyptic number.

28576391 is a deficient number, since it is larger than the sum of its proper divisors (39409).

28576391 is an equidigital number, since it uses as much as digits as its factorization.

28576391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39408.

The product of its digits is 90720, while the sum is 41.

The square root of 28576391 is about 5345.6890107824. The cubic root of 28576391 is about 305.7284068298.

The spelling of 28576391 in words is "twenty-eight million, five hundred seventy-six thousand, three hundred ninety-one".