28578191 has 4 divisors (see below), whose sum is σ = 28722000. Its totient is φ = 28434384.

The previous prime is 28578181. The next prime is 28578197. The reversal of 28578191 is 19187582.

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 28578191 - 2⁶ = 28578127 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28578197) 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, 71606 + ... + 72003.

It is an arithmetic number, because the mean of its divisors is an integer number (7180500).

Almost surely, 2^28578191 is an apocalyptic number.

28578191 is a deficient number, since it is larger than the sum of its proper divisors (143809).

28578191 is a wasteful number, since it uses less digits than its factorization.

28578191 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143808.

The product of its digits is 40320, while the sum is 41.

The square root of 28578191 is about 5345.8573680935. The cubic root of 28578191 is about 305.7348258766.

The spelling of 28578191 in words is "twenty-eight million, five hundred seventy-eight thousand, one hundred ninety-one".