128868865 has 8 divisors (see below), whose sum is σ = 156237480. Its totient is φ = 102031872.

The previous prime is 128868853. The next prime is 128868869. The reversal of 128868865 is 568868821.

It can be written as a sum of positive squares in 4 ways, for example, as 46730896 + 82137969 = 6836^2 + 9063^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128868865 - 2⁵ = 128868833 is a prime.

It is not an unprimeable number, because it can be changed into a prime (128868869) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 132370 + ... + 133339.

It is an arithmetic number, because the mean of its divisors is an integer number (19529685).

Almost surely, 2^128868865 is an apocalyptic number.

It is an amenable number.

128868865 is a deficient number, since it is larger than the sum of its proper divisors (27368615).

128868865 is an equidigital number, since it uses as much as digits as its factorization.

128868865 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 265811.

The product of its digits is 1474560, while the sum is 52.

The square root of 128868865 is about 11352.0423272643. The cubic root of 128868865 is about 505.1061633484.

The spelling of 128868865 in words is "one hundred twenty-eight million, eight hundred sixty-eight thousand, eight hundred sixty-five".