128815361 has 4 divisors (see below), whose sum is σ = 133257300. Its totient is φ = 124373424.

The previous prime is 128815343. The next prime is 128815363. The reversal of 128815361 is 163518821.

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 41280625 + 87534736 = 6425^2 + 9356^2 .

It is a cyclic number.

It is not a de Polignac number, because 128815361 - 2¹⁴ = 128798977 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128815363) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2220926 + ... + 2220983.

It is an arithmetic number, because the mean of its divisors is an integer number (33314325).

Almost surely, 2^128815361 is an apocalyptic number.

It is an amenable number.

128815361 is a deficient number, since it is larger than the sum of its proper divisors (4441939).

128815361 is an equidigital number, since it uses as much as digits as its factorization.

128815361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4441938.

The product of its digits is 11520, while the sum is 35.

The square root of 128815361 is about 11349.6855022507. The cubic root of 128815361 is about 505.0362500528.

The spelling of 128815361 in words is "one hundred twenty-eight million, eight hundred fifteen thousand, three hundred sixty-one".