128444331 has 4 divisors (see below), whose sum is σ = 171259112. Its totient is φ = 85629552.

The previous prime is 128444291. The next prime is 128444339. The reversal of 128444331 is 133444821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 133444821 = 3 ⋅44481607.

It is a de Polignac number, because none of the positive numbers 2^k-128444331 is a prime.

It is a super-2 number, since 2×128444331² = 32995892332075122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128444339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 21407386 + ... + 21407391.

It is an arithmetic number, because the mean of its divisors is an integer number (42814778).

Almost surely, 2^128444331 is an apocalyptic number.

128444331 is a deficient number, since it is larger than the sum of its proper divisors (42814781).

128444331 is an equidigital number, since it uses as much as digits as its factorization.

128444331 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42814780.

The product of its digits is 9216, while the sum is 30.

The square root of 128444331 is about 11333.3283284303. The cubic root of 128444331 is about 504.5508943847.

The spelling of 128444331 in words is "one hundred twenty-eight million, four hundred forty-four thousand, three hundred thirty-one".