128126831 has 4 divisors (see below), whose sum is σ = 146430672. Its totient is φ = 109822992.

The previous prime is 128126827. The next prime is 128126833. The reversal of 128126831 is 138621821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 138621821 = 13 ⋅10663217.

It is a cyclic number.

It is not a de Polignac number, because 128126831 - 2² = 128126827 is a prime.

It is a super-2 number, since 2×128126831² = 32832969644205122, 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 (128126833) 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, 9151910 + ... + 9151923.

It is an arithmetic number, because the mean of its divisors is an integer number (36607668).

Almost surely, 2^128126831 is an apocalyptic number.

128126831 is a deficient number, since it is larger than the sum of its proper divisors (18303841).

128126831 is an equidigital number, since it uses as much as digits as its factorization.

128126831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18303840.

The product of its digits is 4608, while the sum is 32.

The square root of 128126831 is about 11319.3123024325. The cubic root of 128126831 is about 504.1348202668.

The spelling of 128126831 in words is "one hundred twenty-eight million, one hundred twenty-six thousand, eight hundred thirty-one".