813389881 has 2 divisors, whose sum is σ = 813389882. Its totient is φ = 813389880.

The previous prime is 813389851. The next prime is 813389891. The reversal of 813389881 is 188983318.

813389881 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 801795856 + 11594025 = 28316^2 + 3405^2 .

It is a cyclic number.

It is not a de Polignac number, because 813389881 - 2²⁹ = 276518969 is a prime.

It is a super-2 number, since 2×813389881² = 1323206197026388322, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (813389851) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 406694940 + 406694941.

It is an arithmetic number, because the mean of its divisors is an integer number (406694941).

Almost surely, 2^813389881 is an apocalyptic number.

It is an amenable number.

813389881 is a deficient number, since it is larger than the sum of its proper divisors (1).

813389881 is an equidigital number, since it uses as much as digits as its factorization.

813389881 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 331776, while the sum is 49.

The square root of 813389881 is about 28519.9909011206. The cubic root of 813389881 is about 933.4683306290.

It can be divided in two parts, 81338 and 9881, that added together give a palindrome (91219).

The spelling of 813389881 in words is "eight hundred thirteen million, three hundred eighty-nine thousand, eight hundred eighty-one".