128266257 has 16 divisors (see below), whose sum is σ = 198208512. Its totient is φ = 72261840.

The previous prime is 128266223. The next prime is 128266261. The reversal of 128266257 is 752662821.

It is not a de Polignac number, because 128266257 - 2⁷ = 128266129 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128266277) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 41523 + ... + 44504.

It is an arithmetic number, because the mean of its divisors is an integer number (12388032).

Almost surely, 2^128266257 is an apocalyptic number.

It is an amenable number.

128266257 is a deficient number, since it is larger than the sum of its proper divisors (69942255).

128266257 is an equidigital number, since it uses as much as digits as its factorization.

128266257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 86108.

The product of its digits is 80640, while the sum is 39.

The square root of 128266257 is about 11325.4693942459. The cubic root of 128266257 is about 504.3176183590.

The spelling of 128266257 in words is "one hundred twenty-eight million, two hundred sixty-six thousand, two hundred fifty-seven".