128009831 has 12 divisors (see below), whose sum is σ = 132160992. Its totient is φ = 123984000.

The previous prime is 128009809. The next prime is 128009851. The reversal of 128009831 is 138900821.

It is not a de Polignac number, because 128009831 - 2⁶ = 128009767 is a prime.

It is a super-2 number, since 2×128009831² = 32773033665297122, 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 (128009851) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 455411 + ... + 455691.

It is an arithmetic number, because the mean of its divisors is an integer number (11013416).

Almost surely, 2^128009831 is an apocalyptic number.

128009831 is a deficient number, since it is larger than the sum of its proper divisors (4151161).

128009831 is an equidigital number, since it uses as much as digits as its factorization.

128009831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 634 (or 593 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 32.

The square root of 128009831 is about 11314.1429635656. The cubic root of 128009831 is about 503.9813220066.

The spelling of 128009831 in words is "one hundred twenty-eight million, nine thousand, eight hundred thirty-one".