28909879 has 4 divisors (see below), whose sum is σ = 29615040. Its totient is φ = 28204720.

The previous prime is 28909861. The next prime is 28909891. The reversal of 28909879 is 97890982.

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

It is not a de Polignac number, because 28909879 - 2⁵ = 28909847 is a prime.

It is a super-2 number, since 2×28909879² = 1671562207589282, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28909819) 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 3 ways as a sum of consecutive naturals, for example, 352519 + ... + 352600.

It is an arithmetic number, because the mean of its divisors is an integer number (7403760).

Almost surely, 2^28909879 is an apocalyptic number.

28909879 is a deficient number, since it is larger than the sum of its proper divisors (705161).

28909879 is an equidigital number, since it uses as much as digits as its factorization.

28909879 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 705160.

The product of its (nonzero) digits is 653184, while the sum is 52.

The square root of 28909879 is about 5376.7907714547. The cubic root of 28909879 is about 306.9130991504.

It can be divided in two parts, 2890 and 9879, that added together give a square (12769 = 113²).

The spelling of 28909879 in words is "twenty-eight million, nine hundred nine thousand, eight hundred seventy-nine".