100128515 has 4 divisors (see below), whose sum is σ = 120154224. Its totient is φ = 80102808.

The previous prime is 100128491. The next prime is 100128529. The reversal of 100128515 is 515821001.

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 100128515 - 2¹⁰ = 100127491 is a prime.

It is a super-2 number, since 2×100128515² = 20051439032210450, which contains 22 as substring.

It is a Duffinian number.

It is an unprimeable number.

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, 10012847 + ... + 10012856.

It is an arithmetic number, because the mean of its divisors is an integer number (30038556).

Almost surely, 2^100128515 is an apocalyptic number.

100128515 is a deficient number, since it is larger than the sum of its proper divisors (20025709).

100128515 is an equidigital number, since it uses as much as digits as its factorization.

100128515 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20025708.

The product of its (nonzero) digits is 400, while the sum is 23.

The square root of 100128515 is about 10006.4236868124. The cubic root of 100128515 is about 464.3576361728.

Adding to 100128515 its reverse (515821001), we get a palindrome (615949516).

The spelling of 100128515 in words is "one hundred million, one hundred twenty-eight thousand, five hundred fifteen".