128212115 has 4 divisors (see below), whose sum is σ = 153854544. Its totient is φ = 102569688.

The previous prime is 128212109. The next prime is 128212121. The reversal of 128212115 is 511212821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 511212821 = 7 ⋅73030403.

It is an interprime number because it is at equal distance from previous prime (128212109) and next prime (128212121).

It is a cyclic number.

It is not a de Polignac number, because 128212115 - 2¹⁰ = 128211091 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 12821207 + ... + 12821216.

It is an arithmetic number, because the mean of its divisors is an integer number (38463636).

Almost surely, 2^128212115 is an apocalyptic number.

128212115 is a deficient number, since it is larger than the sum of its proper divisors (25642429).

128212115 is an equidigital number, since it uses as much as digits as its factorization.

128212115 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25642428.

The product of its digits is 320, while the sum is 23.

The square root of 128212115 is about 11323.0788657503. The cubic root of 128212115 is about 504.2466498183.

Adding to 128212115 its reverse (511212821), we get a palindrome (639424936).

The spelling of 128212115 in words is "one hundred twenty-eight million, two hundred twelve thousand, one hundred fifteen".