128466664821 has 16 divisors (see below), whose sum is σ = 207622893120. Its totient is φ = 77858584560.

The previous prime is 128466664813. The next prime is 128466664867.

128466664821 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 128466664821 - 2³ = 128466664813 is a prime.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128466664811) 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, 216273550 + ... + 216274143.

It is an arithmetic number, because the mean of its divisors is an integer number (12976430820).

Almost surely, 2^128466664821 is an apocalyptic number.

128466664821 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

128466664821 is a deficient number, since it is larger than the sum of its proper divisors (79156228299).

128466664821 is a wasteful number, since it uses less digits than its factorization.

128466664821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 432547713 (or 432547707 counting only the distinct ones).

The product of its digits is 5308416, while the sum is 54.

The spelling of 128466664821 in words is "one hundred twenty-eight billion, four hundred sixty-six million, six hundred sixty-four thousand, eight hundred twenty-one".