813899872081 has 2 divisors, whose sum is σ = 813899872082. Its totient is φ = 813899872080.

The previous prime is 813899872069. The next prime is 813899872109. The reversal of 813899872081 is 180278998318.

813899872081 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 495031852225 + 318868019856 = 703585^2 + 564684^2 .

It is a cyclic number.

It is not a de Polignac number, because 813899872081 - 2⁹ = 813899871569 is a prime.

It is a super-2 number, since 2×813899872081² (a number of 25 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (813899872021) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 406949936040 + 406949936041.

It is an arithmetic number, because the mean of its divisors is an integer number (406949936041).

Almost surely, 2^813899872081 is an apocalyptic number.

It is an amenable number.

813899872081 is a deficient number, since it is larger than the sum of its proper divisors (1).

813899872081 is an equidigital number, since it uses as much as digits as its factorization.

813899872081 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 13934592, while the sum is 64.

The spelling of 813899872081 in words is "eight hundred thirteen billion, eight hundred ninety-nine million, eight hundred seventy-two thousand, eighty-one".