28807091 has 4 divisors (see below), whose sum is σ = 29736384. Its totient is φ = 27877800.

The previous prime is 28807081. The next prime is 28807139. The reversal of 28807091 is 19070882.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19070882 = 2 ⋅9535441.

It is a cyclic number.

It is not a de Polignac number, because 28807091 - 2¹⁸ = 28544947 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28807001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 464600 + ... + 464661.

It is an arithmetic number, because the mean of its divisors is an integer number (7434096).

Almost surely, 2^28807091 is an apocalyptic number.

28807091 is a deficient number, since it is larger than the sum of its proper divisors (929293).

28807091 is an equidigital number, since it uses as much as digits as its factorization.

28807091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 929292.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 28807091 is about 5367.2237702559. The cubic root of 28807091 is about 306.5489278383.

The spelling of 28807091 in words is "twenty-eight million, eight hundred seven thousand, ninety-one".