28123789 has 8 divisors (see below), whose sum is σ = 29092608. Its totient is φ = 27158880.

The previous prime is 28123787. The next prime is 28123793. The reversal of 28123789 is 98732182.

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 28123789 - 2¹ = 28123787 is a prime.

It is a super-3 number, since 3×28123789³ (a number of 23 digits) contains 333 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 (28123787) 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, 25089 + ... + 26185.

It is an arithmetic number, because the mean of its divisors is an integer number (3636576).

Almost surely, 2^28123789 is an apocalyptic number.

It is an amenable number.

28123789 is a deficient number, since it is larger than the sum of its proper divisors (968819).

28123789 is a wasteful number, since it uses less digits than its factorization.

28123789 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1955.

The product of its digits is 48384, while the sum is 40.

The square root of 28123789 is about 5303.1866834951. The cubic root of 28123789 is about 304.1057349477.

The spelling of 28123789 in words is "twenty-eight million, one hundred twenty-three thousand, seven hundred eighty-nine".