128409231 has 16 divisors (see below), whose sum is σ = 172757600. Its totient is φ = 84837888.

The previous prime is 128409199. The next prime is 128409241. The reversal of 128409231 is 132904821.

It is not a de Polignac number, because 128409231 - 2⁵ = 128409199 is a prime.

It is a super-2 number, since 2×128409231² = 32977861212022722, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128409241) 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, 280755 + ... + 281211.

It is an arithmetic number, because the mean of its divisors is an integer number (10797350).

Almost surely, 2^128409231 is an apocalyptic number.

128409231 is a deficient number, since it is larger than the sum of its proper divisors (44348369).

128409231 is a wasteful number, since it uses less digits than its factorization.

128409231 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1098.

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

The square root of 128409231 is about 11331.7796925284. The cubic root of 128409231 is about 504.5049306335.

The spelling of 128409231 in words is "one hundred twenty-eight million, four hundred nine thousand, two hundred thirty-one".