128106091 has 4 divisors (see below), whose sum is σ = 128129512. Its totient is φ = 128082672.

The previous prime is 128106089. The next prime is 128106103. The reversal of 128106091 is 190601821.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 190601821 = 463 ⋅411667.

It is a cyclic number.

It is not a de Polignac number, because 128106091 - 2¹ = 128106089 is a prime.

It is a super-2 number, since 2×128106091² = 32822341102600562, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128106001) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1351 + ... + 16063.

It is an arithmetic number, because the mean of its divisors is an integer number (32032378).

Almost surely, 2^128106091 is an apocalyptic number.

128106091 is a deficient number, since it is larger than the sum of its proper divisors (23421).

128106091 is an equidigital number, since it uses as much as digits as its factorization.

128106091 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23420.

The product of its (nonzero) digits is 864, while the sum is 28.

The square root of 128106091 is about 11318.3961319615. The cubic root of 128106091 is about 504.1076172204.

The spelling of 128106091 in words is "one hundred twenty-eight million, one hundred six thousand, ninety-one".