28776805 has 4 divisors (see below), whose sum is σ = 34532172. Its totient is φ = 23021440.

The previous prime is 28776799. The next prime is 28776821. The reversal of 28776805 is 50867782.

It is a happy number.

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

It can be written as a sum of positive squares in 2 ways, for example, as 18395521 + 10381284 = 4289^2 + 3222^2 .

It is not a de Polignac number, because 28776805 - 2¹⁹ = 28252517 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2877676 + ... + 2877685.

It is an arithmetic number, because the mean of its divisors is an integer number (8633043).

Almost surely, 2^28776805 is an apocalyptic number.

It is an amenable number.

28776805 is a deficient number, since it is larger than the sum of its proper divisors (5755367).

28776805 is an equidigital number, since it uses as much as digits as its factorization.

28776805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5755366.

The product of its (nonzero) digits is 188160, while the sum is 43.

The square root of 28776805 is about 5364.4016441724. The cubic root of 28776805 is about 306.4414612853.

The spelling of 28776805 in words is "twenty-eight million, seven hundred seventy-six thousand, eight hundred five".