28191433 has 4 divisors (see below), whose sum is σ = 28450180. Its totient is φ = 27932688.

The previous prime is 28191413. The next prime is 28191463. The reversal of 28191433 is 33419182.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 24078649 + 4112784 = 4907^2 + 2028^2 .

It is a cyclic number.

It is not a de Polignac number, because 28191433 - 2¹³ = 28183241 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 28191395 and 28191404.

It is not an unprimeable number, because it can be changed into a prime (28191403) 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 3 ways as a sum of consecutive naturals, for example, 129210 + ... + 129427.

It is an arithmetic number, because the mean of its divisors is an integer number (7112545).

Almost surely, 2^28191433 is an apocalyptic number.

It is an amenable number.

28191433 is a deficient number, since it is larger than the sum of its proper divisors (258747).

28191433 is a wasteful number, since it uses less digits than its factorization.

28191433 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 258746.

The product of its digits is 5184, while the sum is 31.

The square root of 28191433 is about 5309.5605279533. The cubic root of 28191433 is about 304.3493538258.

The spelling of 28191433 in words is "twenty-eight million, one hundred ninety-one thousand, four hundred thirty-three".