128047831 has 4 divisors (see below), whose sum is σ = 133615152. Its totient is φ = 122480512.

The previous prime is 128047823. The next prime is 128047837. The reversal of 128047831 is 138740821.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 128047831 - 2³ = 128047823 is a prime.

It is a super-2 number, since 2×128047831² = 32792494047609122, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (128047837) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2783626 + ... + 2783671.

It is an arithmetic number, because the mean of its divisors is an integer number (33403788).

Almost surely, 2^128047831 is an apocalyptic number.

128047831 is a deficient number, since it is larger than the sum of its proper divisors (5567321).

128047831 is an equidigital number, since it uses as much as digits as its factorization.

128047831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5567320.

The product of its (nonzero) digits is 10752, while the sum is 34.

The square root of 128047831 is about 11315.8221530740. The cubic root of 128047831 is about 504.0311863943.

The spelling of 128047831 in words is "one hundred twenty-eight million, forty-seven thousand, eight hundred thirty-one".