128420511 has 4 divisors (see below), whose sum is σ = 171227352. Its totient is φ = 85613672.

The previous prime is 128420491. The next prime is 128420527. The reversal of 128420511 is 115024821.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128420511 - 2⁶ = 128420447 is a prime.

It is a super-2 number, since 2×128420511² = 32983655291002242, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128420111) 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 3 ways as a sum of consecutive naturals, for example, 21403416 + ... + 21403421.

It is an arithmetic number, because the mean of its divisors is an integer number (42806838).

Almost surely, 2^128420511 is an apocalyptic number.

128420511 is a deficient number, since it is larger than the sum of its proper divisors (42806841).

128420511 is an equidigital number, since it uses as much as digits as its factorization.

128420511 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42806840.

The product of its (nonzero) digits is 640, while the sum is 24.

The square root of 128420511 is about 11332.2773968872. The cubic root of 128420511 is about 504.5197028035.

The spelling of 128420511 in words is "one hundred twenty-eight million, four hundred twenty thousand, five hundred eleven".