812556531641 has 4 divisors (see below), whose sum is σ = 812558375412. Its totient is φ = 812554687872.

The previous prime is 812556531613. The next prime is 812556531679. The reversal of 812556531641 is 146135655218.

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 637578295225 + 174978236416 = 798485^2 + 418304^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-812556531641 is a prime.

It is a super-2 number, since 2×812556531641² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (812556531601) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 171185 + ... + 1286241.

It is an arithmetic number, because the mean of its divisors is an integer number (203139593853).

Almost surely, 2^812556531641 is an apocalyptic number.

It is an amenable number.

812556531641 is a deficient number, since it is larger than the sum of its proper divisors (1843771).

812556531641 is a wasteful number, since it uses less digits than its factorization.

812556531641 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1843770.

The product of its digits is 864000, while the sum is 47.

The spelling of 812556531641 in words is "eight hundred twelve billion, five hundred fifty-six million, five hundred thirty-one thousand, six hundred forty-one".