28578817 has 4 divisors (see below), whose sum is σ = 28784560. Its totient is φ = 28373076.

The previous prime is 28578791. The next prime is 28578821. The reversal of 28578817 is 71887582.

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 a de Polignac number, because none of the positive numbers 2^k-28578817 is a prime.

It is a super-2 number, since 2×28578817² = 1633497562238978, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28578217) 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, 102663 + ... + 102940.

It is an arithmetic number, because the mean of its divisors is an integer number (7196140).

Almost surely, 2^28578817 is an apocalyptic number.

It is an amenable number.

28578817 is a deficient number, since it is larger than the sum of its proper divisors (205743).

28578817 is a wasteful number, since it uses less digits than its factorization.

28578817 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205742.

The product of its digits is 250880, while the sum is 46.

The square root of 28578817 is about 5345.9159177825. The cubic root of 28578817 is about 305.7370582153.

The spelling of 28578817 in words is "twenty-eight million, five hundred seventy-eight thousand, eight hundred seventeen".