28749779 has 4 divisors (see below), whose sum is σ = 28784184. Its totient is φ = 28715376.

The previous prime is 28749719. The next prime is 28749811. The reversal of 28749779 is 97794782.

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 28749779 - 2²⁰ = 27701203 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 28749779.

It is not an unprimeable number, because it can be changed into a prime (28749719) 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, 15917 + ... + 17630.

It is an arithmetic number, because the mean of its divisors is an integer number (7196046).

Almost surely, 2^28749779 is an apocalyptic number.

28749779 is a deficient number, since it is larger than the sum of its proper divisors (34405).

28749779 is an equidigital number, since it uses as much as digits as its factorization.

28749779 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34404.

The product of its digits is 1778112, while the sum is 53.

The square root of 28749779 is about 5361.8820389859. The cubic root of 28749779 is about 306.3454988026.

The spelling of 28749779 in words is "twenty-eight million, seven hundred forty-nine thousand, seven hundred seventy-nine".