128378964121 has 16 divisors (see below), whose sum is σ = 133555651200. Its totient is φ = 123300455040.

The previous prime is 128378964059. The next prime is 128378964187. The reversal of 128378964121 is 121469873821.

It is a cyclic number.

It is not a de Polignac number, because 128378964121 - 2¹¹ = 128378962073 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128378964221) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1054780 + ... + 1170178.

It is an arithmetic number, because the mean of its divisors is an integer number (8347228200).

Almost surely, 2^128378964121 is an apocalyptic number.

It is an amenable number.

128378964121 is a deficient number, since it is larger than the sum of its proper divisors (5176687079).

128378964121 is a wasteful number, since it uses less digits than its factorization.

128378964121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 115824.

The product of its digits is 1161216, while the sum is 52.

The spelling of 128378964121 in words is "one hundred twenty-eight billion, three hundred seventy-eight million, nine hundred sixty-four thousand, one hundred twenty-one".