28158191 has 2 divisors, whose sum is σ = 28158192. Its totient is φ = 28158190.

The previous prime is 28158181. The next prime is 28158257. The reversal of 28158191 is 19185182.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 28158191 - 2¹⁴ = 28141807 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (28158181) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 14079095 + 14079096.

It is an arithmetic number, because the mean of its divisors is an integer number (14079096).

Almost surely, 2^28158191 is an apocalyptic number.

28158191 is a deficient number, since it is larger than the sum of its proper divisors (1).

28158191 is an equidigital number, since it uses as much as digits as its factorization.

28158191 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5760, while the sum is 35.

The square root of 28158191 is about 5306.4292136992. The cubic root of 28158191 is about 304.2296820045.

The spelling of 28158191 in words is "twenty-eight million, one hundred fifty-eight thousand, one hundred ninety-one".