128255591 has 2 divisors, whose sum is σ = 128255592. Its totient is φ = 128255590.

The previous prime is 128255581. The next prime is 128255639. The reversal of 128255591 is 195552821.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 128255591 - 2¹⁴ = 128239207 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (128255581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 64127795 + 64127796.

It is an arithmetic number, because the mean of its divisors is an integer number (64127796).

Almost surely, 2^128255591 is an apocalyptic number.

128255591 is a deficient number, since it is larger than the sum of its proper divisors (1).

128255591 is an equidigital number, since it uses as much as digits as its factorization.

128255591 is an evil number, because the sum of its binary digits is even.

The product of its digits is 36000, while the sum is 38.

The square root of 128255591 is about 11324.9984988961. The cubic root of 128255591 is about 504.3036391022.

The spelling of 128255591 in words is "one hundred twenty-eight million, two hundred fifty-five thousand, five hundred ninety-one".