128320121215786 has 16 divisors (see below), whose sum is σ = 207647876509704. Its totient is φ = 59246582047744.

The previous prime is 128320121215753. The next prime is 128320121215789. The reversal of 128320121215786 is 687512121023821.

It can be written as a sum of positive squares in 4 ways, for example, as 107815390129561 + 20504731086225 = 10383419^2 + 4528215^2 .

It is not an unprimeable number, because it can be changed into a prime (128320121215789) 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, 35604915295 + ... + 35604918898.

Almost surely, 2^{128320121215786} is an apocalyptic number.

128320121215786 is a deficient number, since it is larger than the sum of its proper divisors (79327755293918).

128320121215786 is a wasteful number, since it uses less digits than its factorization.

128320121215786 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 71209834265.

The product of its (nonzero) digits is 645120, while the sum is 49.

The spelling of 128320121215786 in words is "one hundred twenty-eight trillion, three hundred twenty billion, one hundred twenty-one million, two hundred fifteen thousand, seven hundred eighty-six".