28389831 has 8 divisors (see below), whose sum is σ = 39074304. Its totient is φ = 18315960.

The previous prime is 28389793. The next prime is 28389853. The reversal of 28389831 is 13898382.

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

It is not a de Polignac number, because 28389831 - 2¹⁰ = 28388807 is a prime.

It is a super-2 number, since 2×28389831² = 1611965008417122, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28389631) 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 7 ways as a sum of consecutive naturals, for example, 152541 + ... + 152726.

It is an arithmetic number, because the mean of its divisors is an integer number (4884288).

Almost surely, 2^28389831 is an apocalyptic number.

28389831 is a deficient number, since it is larger than the sum of its proper divisors (10684473).

28389831 is a wasteful number, since it uses less digits than its factorization.

28389831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 305301.

The product of its digits is 82944, while the sum is 42.

The square root of 28389831 is about 5328.2108629445. The cubic root of 28389831 is about 305.0616412187.

The spelling of 28389831 in words is "twenty-eight million, three hundred eighty-nine thousand, eight hundred thirty-one".