81334673293 has 2 divisors, whose sum is σ = 81334673294. Its totient is φ = 81334673292.

The previous prime is 81334673291. The next prime is 81334673347. The reversal of 81334673293 is 39237643318.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 80362044324 + 972628969 = 283482^2 + 31187^2 .

It is a cyclic number.

It is not a de Polignac number, because 81334673293 - 2¹ = 81334673291 is a prime.

Together with 81334673291, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81334673291) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40667336646 + 40667336647.

It is an arithmetic number, because the mean of its divisors is an integer number (40667336647).

Almost surely, 2^81334673293 is an apocalyptic number.

It is an amenable number.

81334673293 is a deficient number, since it is larger than the sum of its proper divisors (1).

81334673293 is an equidigital number, since it uses as much as digits as its factorization.

81334673293 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1959552, while the sum is 49.

The spelling of 81334673293 in words is "eighty-one billion, three hundred thirty-four million, six hundred seventy-three thousand, two hundred ninety-three".