812128445 has 4 divisors (see below), whose sum is σ = 974554140. Its totient is φ = 649702752.

The previous prime is 812128409. The next prime is 812128469. The reversal of 812128445 is 544821218.

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

It can be written as a sum of positive squares in 2 ways, for example, as 504406681 + 307721764 = 22459^2 + 17542^2 .

It is a cyclic number.

It is not a de Polignac number, because 812128445 - 2¹² = 812124349 is a prime.

It is a super-2 number, since 2×812128445² = 1319105222356236050, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 81212840 + ... + 81212849.

It is an arithmetic number, because the mean of its divisors is an integer number (243638535).

Almost surely, 2^812128445 is an apocalyptic number.

It is an amenable number.

812128445 is a deficient number, since it is larger than the sum of its proper divisors (162425695).

812128445 is a wasteful number, since it uses less digits than its factorization.

812128445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 162425694.

The product of its digits is 20480, while the sum is 35.

The square root of 812128445 is about 28497.8673763494. The cubic root of 812128445 is about 932.9855282161.

The spelling of 812128445 in words is "eight hundred twelve million, one hundred twenty-eight thousand, four hundred forty-five".