128304445721 has 8 divisors (see below), whose sum is σ = 129028605888. Its totient is φ = 127580454000.

The previous prime is 128304445673. The next prime is 128304445739. The reversal of 128304445721 is 127544403821.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 128304445721 - 2¹⁸ = 128304183577 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (128304445121) 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, 1684226 + ... + 1758756.

It is an arithmetic number, because the mean of its divisors is an integer number (16128575736).

Almost surely, 2^128304445721 is an apocalyptic number.

It is an amenable number.

128304445721 is a deficient number, since it is larger than the sum of its proper divisors (724160167).

128304445721 is an equidigital number, since it uses as much as digits as its factorization.

128304445721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 84223.

The product of its (nonzero) digits is 215040, while the sum is 41.

The spelling of 128304445721 in words is "one hundred twenty-eight billion, three hundred four million, four hundred forty-five thousand, seven hundred twenty-one".