128261511 has 36 divisors (see below), whose sum is σ = 215926672. Its totient is φ = 71855424.

The previous prime is 128261459. The next prime is 128261513. The reversal of 128261511 is 115162821.

128261511 is a `hidden beast` number, since 12 + 82 + 61 + 511 = 666.

It is not a de Polignac number, because 128261511 - 2¹⁰ = 128260487 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128261513) by changing a digit.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 767950 + ... + 768116.

Almost surely, 2^128261511 is an apocalyptic number.

128261511 is a deficient number, since it is larger than the sum of its proper divisors (87665161).

128261511 is an equidigital number, since it uses as much as digits as its factorization.

128261511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 420 (or 250 counting only the distinct ones).

The product of its digits is 960, while the sum is 27.

The square root of 128261511 is about 11325.2598645682. The cubic root of 128261511 is about 504.3113981704.

The spelling of 128261511 in words is "one hundred twenty-eight million, two hundred sixty-one thousand, five hundred eleven".