128205715 has 16 divisors (see below), whose sum is σ = 168280416. Its totient is φ = 92992000.

The previous prime is 128205697. The next prime is 128205719. The reversal of 128205715 is 517502821.

It is not a de Polignac number, because 128205715 - 2⁵ = 128205683 is a prime.

It is a super-2 number, since 2×128205715² = 32873410717322450, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128205719) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19149 + ... + 24961.

It is an arithmetic number, because the mean of its divisors is an integer number (10517526).

Almost surely, 2^128205715 is an apocalyptic number.

128205715 is a deficient number, since it is larger than the sum of its proper divisors (40074701).

128205715 is a wasteful number, since it uses less digits than its factorization.

128205715 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6230.

The product of its (nonzero) digits is 5600, while the sum is 31.

The square root of 128205715 is about 11322.7962535762. The cubic root of 128205715 is about 504.2382594717.

The spelling of 128205715 in words is "one hundred twenty-eight million, two hundred five thousand, seven hundred fifteen".