28154191 has 4 divisors (see below), whose sum is σ = 30319912. Its totient is φ = 25988472.

The previous prime is 28154177. The next prime is 28154197. The reversal of 28154191 is 19145182.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 28154191 - 2²³ = 19765583 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (28154197) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1082841 + ... + 1082866.

It is an arithmetic number, because the mean of its divisors is an integer number (7579978).

Almost surely, 2^28154191 is an apocalyptic number.

28154191 is a deficient number, since it is larger than the sum of its proper divisors (2165721).

28154191 is a wasteful number, since it uses less digits than its factorization.

28154191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2165720.

The product of its digits is 2880, while the sum is 31.

The square root of 28154191 is about 5306.0522990261. The cubic root of 28154191 is about 304.2152755824.

Subtracting from 28154191 its reverse (19145182), we obtain a palindrome (9009009).

The spelling of 28154191 in words is "twenty-eight million, one hundred fifty-four thousand, one hundred ninety-one".