128217601 has 4 divisors (see below), whose sum is σ = 128376900. Its totient is φ = 128058304.

The previous prime is 128217599. The next prime is 128217667. The reversal of 128217601 is 106712821.

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

It can be written as a sum of positive squares in 2 ways, for example, as 42562576 + 85655025 = 6524^2 + 9255^2 .

It is a cyclic number.

It is not a de Polignac number, because 128217601 - 2¹ = 128217599 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 128217601.

It is not an unprimeable number, because it can be changed into a prime (128247601) 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 3 ways as a sum of consecutive naturals, for example, 78436 + ... + 80053.

It is an arithmetic number, because the mean of its divisors is an integer number (32094225).

Almost surely, 2^128217601 is an apocalyptic number.

It is an amenable number.

128217601 is a deficient number, since it is larger than the sum of its proper divisors (159299).

128217601 is an equidigital number, since it uses as much as digits as its factorization.

128217601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 159298.

The product of its (nonzero) digits is 1344, while the sum is 28.

The square root of 128217601 is about 11323.3211117587. The cubic root of 128217601 is about 504.2538416963.

The spelling of 128217601 in words is "one hundred twenty-eight million, two hundred seventeen thousand, six hundred one".