128812031 has 4 divisors (see below), whose sum is σ = 128910864. Its totient is φ = 128713200.

The previous prime is 128812003. The next prime is 128812049. The reversal of 128812031 is 130218821.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 130218821 = 181 ⋅719441.

It is a cyclic number.

It is not a de Polignac number, because 128812031 - 2¹⁸ = 128549887 is a prime.

It is a super-2 number, since 2×128812031² = 33185078660689922, 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 (128812051) 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, 47435 + ... + 50076.

It is an arithmetic number, because the mean of its divisors is an integer number (32227716).

Almost surely, 2^128812031 is an apocalyptic number.

128812031 is a deficient number, since it is larger than the sum of its proper divisors (98833).

128812031 is an equidigital number, since it uses as much as digits as its factorization.

128812031 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 98832.

The product of its (nonzero) digits is 768, while the sum is 26.

The square root of 128812031 is about 11349.5388012025. The cubic root of 128812031 is about 505.0318981256.

The spelling of 128812031 in words is "one hundred twenty-eight million, eight hundred twelve thousand, thirty-one".