128946391 has 32 divisors (see below), whose sum is σ = 158412800. Its totient is φ = 104781600.

The previous prime is 128946359. The next prime is 128946401. The reversal of 128946391 is 193649821.

It is a happy number.

It is not a de Polignac number, because 128946391 - 2⁵ = 128946359 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128946491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 712321 + ... + 712501.

It is an arithmetic number, because the mean of its divisors is an integer number (4950400).

Almost surely, 2^128946391 is an apocalyptic number.

128946391 is a deficient number, since it is larger than the sum of its proper divisors (29466409).

128946391 is an equidigital number, since it uses as much as digits as its factorization.

128946391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 300 (or 286 counting only the distinct ones).

The product of its digits is 93312, while the sum is 43.

The square root of 128946391 is about 11355.4564417288. The cubic root of 128946391 is about 505.2074316947.

The spelling of 128946391 in words is "one hundred twenty-eight million, nine hundred forty-six thousand, three hundred ninety-one".