128427309 has 16 divisors (see below), whose sum is σ = 191332800. Its totient is φ = 85136688.

The previous prime is 128427307. The next prime is 128427323. The reversal of 128427309 is 903724821.

It is not a de Polignac number, because 128427309 - 2¹ = 128427307 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128427307) 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, 8454 + ... + 18119.

It is an arithmetic number, because the mean of its divisors is an integer number (11958300).

Almost surely, 2^128427309 is an apocalyptic number.

It is an amenable number.

128427309 is a deficient number, since it is larger than the sum of its proper divisors (62905491).

128427309 is a wasteful number, since it uses less digits than its factorization.

128427309 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 26761 (or 26755 counting only the distinct ones).

The product of its (nonzero) digits is 24192, while the sum is 36.

The square root of 128427309 is about 11332.5773326283. The cubic root of 128427309 is about 504.5286049755.

The spelling of 128427309 in words is "one hundred twenty-eight million, four hundred twenty-seven thousand, three hundred nine".