28578813 has 4 divisors (see below), whose sum is σ = 38105088. Its totient is φ = 19052540.

The previous prime is 28578791. The next prime is 28578821. The reversal of 28578813 is 31887582.

It is a happy number.

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 28578813 - 2⁶ = 28578749 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28578863) 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, 4763133 + ... + 4763138.

It is an arithmetic number, because the mean of its divisors is an integer number (9526272).

Almost surely, 2^28578813 is an apocalyptic number.

It is an amenable number.

28578813 is a deficient number, since it is larger than the sum of its proper divisors (9526275).

28578813 is an equidigital number, since it uses as much as digits as its factorization.

28578813 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9526274.

The product of its digits is 107520, while the sum is 42.

The square root of 28578813 is about 5345.9155436651. The cubic root of 28578813 is about 305.7370439513.

The spelling of 28578813 in words is "twenty-eight million, five hundred seventy-eight thousand, eight hundred thirteen".