28879729 has 4 divisors (see below), whose sum is σ = 28890484. Its totient is φ = 28868976.

The previous prime is 28879727. The next prime is 28879759. The reversal of 28879729 is 92797882.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 21372129 + 7507600 = 4623^2 + 2740^2 .

It is a cyclic number.

It is not a de Polignac number, because 28879729 - 2¹ = 28879727 is a prime.

It is a super-2 number, since 2×28879729² = 1668077494226882, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (28879723) 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, 2419 + ... + 7975.

It is an arithmetic number, because the mean of its divisors is an integer number (7222621).

Almost surely, 2^28879729 is an apocalyptic number.

It is an amenable number.

28879729 is a deficient number, since it is larger than the sum of its proper divisors (10755).

28879729 is an equidigital number, since it uses as much as digits as its factorization.

28879729 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10754.

The product of its digits is 1016064, while the sum is 52.

The square root of 28879729 is about 5373.9863230194. The cubic root of 28879729 is about 306.8063692146.

The spelling of 28879729 in words is "twenty-eight million, eight hundred seventy-nine thousand, seven hundred twenty-nine".