812128005 has 64 divisors (see below), whose sum is σ = 1560384000. Its totient is φ = 398393856.

The previous prime is 812127997. The next prime is 812128013. The reversal of 812128005 is 500821218.

It is an interprime number because it is at equal distance from previous prime (812127997) and next prime (812128013).

It is not a de Polignac number, because 812128005 - 2³ = 812127997 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a self number, because there is not a number n which added to its sum of digits gives 812128005.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 629401 + ... + 630689.

It is an arithmetic number, because the mean of its divisors is an integer number (24381000).

Almost surely, 2^812128005 is an apocalyptic number.

It is an amenable number.

812128005 is a deficient number, since it is larger than the sum of its proper divisors (748255995).

812128005 is a wasteful number, since it uses less digits than its factorization.

812128005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1675 (or 1669 counting only the distinct ones).

The product of its (nonzero) digits is 1280, while the sum is 27.

The square root of 812128005 is about 28497.8596564724. The cubic root of 812128005 is about 932.9853597231.

The spelling of 812128005 in words is "eight hundred twelve million, one hundred twenty-eight thousand, five".