128187886361 has 4 divisors (see below), whose sum is σ = 128190779172. Its totient is φ = 128184993552.

The previous prime is 128187886357. The next prime is 128187886363. The reversal of 128187886361 is 163688781821.

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 26914371136 + 101273515225 = 164056^2 + 318235^2 .

It is a cyclic number.

It is not a de Polignac number, because 128187886361 - 2² = 128187886357 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 128187886361.

It is not an unprimeable number, because it can be changed into a prime (128187886363) 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, 1378886 + ... + 1468911.

It is an arithmetic number, because the mean of its divisors is an integer number (32047694793).

Almost surely, 2^128187886361 is an apocalyptic number.

It is an amenable number.

128187886361 is a deficient number, since it is larger than the sum of its proper divisors (2892811).

128187886361 is an equidigital number, since it uses as much as digits as its factorization.

128187886361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2892810.

The product of its digits is 6193152, while the sum is 59.

The spelling of 128187886361 in words is "one hundred twenty-eight billion, one hundred eighty-seven million, eight hundred eighty-six thousand, three hundred sixty-one".