28787979 has 16 divisors (see below), whose sum is σ = 42209280. Its totient is φ = 17307360.

The previous prime is 28787977. The next prime is 28787989. The reversal of 28787979 is 97978782.

It is not a de Polignac number, because 28787979 - 2¹ = 28787977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (28787971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 757 + ... + 7625.

It is an arithmetic number, because the mean of its divisors is an integer number (2638080).

Almost surely, 2^28787979 is an apocalyptic number.

28787979 is a deficient number, since it is larger than the sum of its proper divisors (13421301).

28787979 is a wasteful number, since it uses less digits than its factorization.

28787979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7010.

The product of its digits is 3556224, while the sum is 57.

The square root of 28787979 is about 5365.4430385570. The cubic root of 28787979 is about 306.4811197739.

The spelling of 28787979 in words is "twenty-eight million, seven hundred eighty-seven thousand, nine hundred seventy-nine".