128352221 has 4 divisors (see below), whose sum is σ = 128479200. Its totient is φ = 128225244.

The previous prime is 128352209. The next prime is 128352229. The reversal of 128352221 is 122253821.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 128352221 - 2⁶ = 128352157 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 (128352229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 61961 + ... + 63998.

It is an arithmetic number, because the mean of its divisors is an integer number (32119800).

Almost surely, 2^128352221 is an apocalyptic number.

It is an amenable number.

128352221 is a deficient number, since it is larger than the sum of its proper divisors (126979).

128352221 is a wasteful number, since it uses less digits than its factorization.

128352221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126978.

The product of its digits is 1920, while the sum is 26.

The square root of 128352221 is about 11329.2639213675. The cubic root of 128352221 is about 504.4302576955.

The spelling of 128352221 in words is "one hundred twenty-eight million, three hundred fifty-two thousand, two hundred twenty-one".