128121215 has 8 divisors (see below), whose sum is σ = 154104768. Its totient is φ = 102257440.

The previous prime is 128121211. The next prime is 128121221. The reversal of 128121215 is 512121821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 128121215 - 2² = 128121211 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128121211) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 27572 + ... + 31881.

It is an arithmetic number, because the mean of its divisors is an integer number (19263096).

Almost surely, 2^128121215 is an apocalyptic number.

128121215 is a deficient number, since it is larger than the sum of its proper divisors (25983553).

128121215 is an equidigital number, since it uses as much as digits as its factorization.

128121215 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59889.

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

The square root of 128121215 is about 11319.0642281065. The cubic root of 128121215 is about 504.1274544858.

The spelling of 128121215 in words is "one hundred twenty-eight million, one hundred twenty-one thousand, two hundred fifteen".