28191458 has 4 divisors (see below), whose sum is σ = 42287190. Its totient is φ = 14095728.

The previous prime is 28191413. The next prime is 28191463. The reversal of 28191458 is 85419182.

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

It can be written as a sum of positive squares in only one way, i.e., 15108769 + 13082689 = 3887^2 + 3617^2 .

It is a Curzon number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 7047863 + ... + 7047866.

Almost surely, 2^28191458 is an apocalyptic number.

28191458 is a deficient number, since it is larger than the sum of its proper divisors (14095732).

28191458 is a wasteful number, since it uses less digits than its factorization.

28191458 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14095731.

The product of its digits is 23040, while the sum is 38.

The square root of 28191458 is about 5309.5628821966. The cubic root of 28191458 is about 304.3494437909.

The spelling of 28191458 in words is "twenty-eight million, one hundred ninety-one thousand, four hundred fifty-eight".