128221293 has 16 divisors (see below), whose sum is σ = 182891520. Its totient is φ = 79620096.

The previous prime is 128221283. The next prime is 128221307. The reversal of 128221293 is 392122821.

It is not a de Polignac number, because 128221293 - 2⁶ = 128221229 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 128221293.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128221283) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 8013 + ... + 17906.

It is an arithmetic number, because the mean of its divisors is an integer number (11430720).

Almost surely, 2^128221293 is an apocalyptic number.

It is an amenable number.

128221293 is a deficient number, since it is larger than the sum of its proper divisors (54670227).

128221293 is a wasteful number, since it uses less digits than its factorization.

128221293 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26036.

The product of its digits is 3456, while the sum is 30.

The square root of 128221293 is about 11323.4841369607. The cubic root of 128221293 is about 504.2586816125.

The spelling of 128221293 in words is "one hundred twenty-eight million, two hundred twenty-one thousand, two hundred ninety-three".