28742879 has 4 divisors (see below), whose sum is σ = 31355880. Its totient is φ = 26129880.

The previous prime is 28742873. The next prime is 28742887. The reversal of 28742879 is 97824782.

It is a happy number.

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 28742879 - 2⁴ = 28742863 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28742873) 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, 1306484 + ... + 1306505.

It is an arithmetic number, because the mean of its divisors is an integer number (7838970).

Almost surely, 2^28742879 is an apocalyptic number.

28742879 is a deficient number, since it is larger than the sum of its proper divisors (2613001).

28742879 is a wasteful number, since it uses less digits than its factorization.

28742879 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2613000.

The product of its digits is 451584, while the sum is 47.

The square root of 28742879 is about 5361.2385695845. The cubic root of 28742879 is about 306.3209890134.

The spelling of 28742879 in words is "twenty-eight million, seven hundred forty-two thousand, eight hundred seventy-nine".