128332991 has 2 divisors, whose sum is σ = 128332992. Its totient is φ = 128332990.

The previous prime is 128332979. The next prime is 128333021. The reversal of 128332991 is 199233821.

It is a weak prime.

It is an emirp because it is prime and its reverse (199233821) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 128332991 - 2¹⁰ = 128331967 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128332931) 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 as a sum of consecutive naturals, namely, 64166495 + 64166496.

It is an arithmetic number, because the mean of its divisors is an integer number (64166496).

Almost surely, 2^128332991 is an apocalyptic number.

128332991 is a deficient number, since it is larger than the sum of its proper divisors (1).

128332991 is an equidigital number, since it uses as much as digits as its factorization.

128332991 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 23328, while the sum is 38.

The square root of 128332991 is about 11328.4152024897. The cubic root of 128332991 is about 504.4050648362.

The spelling of 128332991 in words is "one hundred twenty-eight million, three hundred thirty-two thousand, nine hundred ninety-one".