105128191 has 4 divisors (see below), whose sum is σ = 120146512. Its totient is φ = 90109872.

The previous prime is 105128189. The next prime is 105128207. The reversal of 105128191 is 191821501.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 191821501 = 157 ⋅1221793.

It is a cyclic number.

It is not a de Polignac number, because 105128191 - 2¹ = 105128189 is a prime.

It is a super-2 number, since 2×105128191² = 22103873085864962, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (105126191) 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, 7509150 + ... + 7509163.

It is an arithmetic number, because the mean of its divisors is an integer number (30036628).

Almost surely, 2^105128191 is an apocalyptic number.

105128191 is a deficient number, since it is larger than the sum of its proper divisors (15018321).

105128191 is an equidigital number, since it uses as much as digits as its factorization.

105128191 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15018320.

The product of its (nonzero) digits is 720, while the sum is 28.

The square root of 105128191 is about 10253.2039382819. The cubic root of 105128191 is about 471.9613091310.

Adding to 105128191 its reverse (191821501), we get a palindrome (296949692).

The spelling of 105128191 in words is "one hundred five million, one hundred twenty-eight thousand, one hundred ninety-one".