28299389 has 8 divisors (see below), whose sum is σ = 29990520. Its totient is φ = 26656000.

The previous prime is 28299377. The next prime is 28299391. The reversal of 28299389 is 98399282.

It can be written as a sum of positive squares in 4 ways, for example, as 1776889 + 26522500 = 1333^2 + 5150^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 28299389 - 2¹⁶ = 28233853 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 (28299889) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10712 + ... + 13089.

It is an arithmetic number, because the mean of its divisors is an integer number (3748815).

Almost surely, 2^28299389 is an apocalyptic number.

28299389 is a gapful number since it is divisible by the number (29) formed by its first and last digit.

It is an amenable number.

28299389 is a deficient number, since it is larger than the sum of its proper divisors (1691131).

28299389 is a wasteful number, since it uses less digits than its factorization.

28299389 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23871.

The product of its digits is 559872, while the sum is 50.

The square root of 28299389 is about 5319.7170037512. The cubic root of 28299389 is about 304.7373498046.

The spelling of 28299389 in words is "twenty-eight million, two hundred ninety-nine thousand, three hundred eighty-nine".