28742869 has 4 divisors (see below), whose sum is σ = 30433644. Its totient is φ = 27052096.

The previous prime is 28742867. The next prime is 28742873. The reversal of 28742869 is 96824782.

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

It can be written as a sum of positive squares in 2 ways, for example, as 17114769 + 11628100 = 4137^2 + 3410^2 .

It is a cyclic number.

It is not a de Polignac number, because 28742869 - 2¹ = 28742867 is a prime.

It is a super-2 number, since 2×28742869² = 1652305036702322, 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 (28742863) 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, 845362 + ... + 845395.

It is an arithmetic number, because the mean of its divisors is an integer number (7608411).

Almost surely, 2^28742869 is an apocalyptic number.

It is an amenable number.

28742869 is a deficient number, since it is larger than the sum of its proper divisors (1690775).

28742869 is a wasteful number, since it uses less digits than its factorization.

28742869 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1690774.

The product of its digits is 387072, while the sum is 46.

The square root of 28742869 is about 5361.2376369641. The cubic root of 28742869 is about 306.3209534891.

The spelling of 28742869 in words is "twenty-eight million, seven hundred forty-two thousand, eight hundred sixty-nine".