28189331 has 8 divisors (see below), whose sum is σ = 30305280. Its totient is φ = 26136648.

The previous prime is 28189309. The next prime is 28189393. The reversal of 28189331 is 13398182.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-28189331 is a prime.

It is a super-2 number, since 2×28189331² = 1589276764455122, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28189291 and 28189300.

It is not an unprimeable number, because it can be changed into a prime (28185331) 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, 14891 + ... + 16676.

It is an arithmetic number, because the mean of its divisors is an integer number (3788160).

Almost surely, 2^28189331 is an apocalyptic number.

28189331 is a deficient number, since it is larger than the sum of its proper divisors (2115949).

28189331 is a wasteful number, since it uses less digits than its factorization.

28189331 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 31633.

The product of its digits is 10368, while the sum is 35.

The square root of 28189331 is about 5309.3625794440. The cubic root of 28189331 is about 304.3417893736.

The spelling of 28189331 in words is "twenty-eight million, one hundred eighty-nine thousand, three hundred thirty-one".