100128105 has 144 divisors (see below), whose sum is σ = 227066112. Its totient is φ = 39916800.

The previous prime is 100128103. The next prime is 100128107. The reversal of 100128105 is 501821001.

It is an interprime number because it is at equal distance from previous prime (100128103) and next prime (100128107).

It is not a de Polignac number, because 100128105 - 2¹ = 100128103 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (100128101) by changing a digit.

It is a polite number, since it can be written in 143 ways as a sum of consecutive naturals, for example, 1410220 + ... + 1410290.

It is an arithmetic number, because the mean of its divisors is an integer number (1576848).

Almost surely, 2^100128105 is an apocalyptic number.

100128105 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

100128105 is an abundant number, since it is smaller than the sum of its proper divisors (126938007).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

100128105 is a wasteful number, since it uses less digits than its factorization.

100128105 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 148 (or 134 counting only the distinct ones).

The product of its (nonzero) digits is 80, while the sum is 18.

The square root of 100128105 is about 10006.4031999515. The cubic root of 100128105 is about 464.3570023644.

Adding to 100128105 its reverse (501821001), we get a palindrome (601949106).

The spelling of 100128105 in words is "one hundred million, one hundred twenty-eight thousand, one hundred five".