128215851 has 8 divisors (see below), whose sum is σ = 174180240. Its totient is φ = 83864352.

The previous prime is 128215849. The next prime is 128215889. The reversal of 128215851 is 158512821.

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

It is not a de Polignac number, because 128215851 - 2¹ = 128215849 is a prime.

It is a super-3 number, since 3×128215851³ (a number of 25 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (128215951) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 403036 + ... + 403353.

It is an arithmetic number, because the mean of its divisors is an integer number (21772530).

Almost surely, 2^128215851 is an apocalyptic number.

128215851 is a deficient number, since it is larger than the sum of its proper divisors (45964389).

128215851 is an equidigital number, since it uses as much as digits as its factorization.

128215851 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 806445.

The product of its digits is 6400, while the sum is 33.

The square root of 128215851 is about 11323.2438373463. The cubic root of 128215851 is about 504.2515475541.

The spelling of 128215851 in words is "one hundred twenty-eight million, two hundred fifteen thousand, eight hundred fifty-one".