812988116581 has 2 divisors, whose sum is σ = 812988116582. Its totient is φ = 812988116580.

The previous prime is 812988116561. The next prime is 812988116657. The reversal of 812988116581 is 185611889218.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 787958028900 + 25030087681 = 887670^2 + 158209^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-812988116581 is a prime.

It is a super-2 number, since 2×812988116581² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (812988116561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 406494058290 + 406494058291.

It is an arithmetic number, because the mean of its divisors is an integer number (406494058291).

Almost surely, 2^812988116581 is an apocalyptic number.

It is an amenable number.

812988116581 is a deficient number, since it is larger than the sum of its proper divisors (1).

812988116581 is an equidigital number, since it uses as much as digits as its factorization.

812988116581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2211840, while the sum is 58.

The spelling of 812988116581 in words is "eight hundred twelve billion, nine hundred eighty-eight million, one hundred sixteen thousand, five hundred eighty-one".