28398831 has 8 divisors (see below), whose sum is σ = 38579760. Its totient is φ = 18575232.

The previous prime is 28398829. The next prime is 28398833. The reversal of 28398831 is 13889382.

It is an interprime number because it is at equal distance from previous prime (28398829) and next prime (28398833).

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

It is not a de Polignac number, because 28398831 - 2¹ = 28398829 is a prime.

It is a super-2 number, since 2×28398831² = 1612987204333122, which contains 22 as substring.

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28398833) 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, 89146 + ... + 89463.

It is an arithmetic number, because the mean of its divisors is an integer number (4822470).

Almost surely, 2^28398831 is an apocalyptic number.

28398831 is a deficient number, since it is larger than the sum of its proper divisors (10180929).

28398831 is a wasteful number, since it uses less digits than its factorization.

28398831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 178665.

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

The square root of 28398831 is about 5329.0553571904. The cubic root of 28398831 is about 305.0938741767.

The spelling of 28398831 in words is "twenty-eight million, three hundred ninety-eight thousand, eight hundred thirty-one".