81314792213 has 2 divisors, whose sum is σ = 81314792214. Its totient is φ = 81314792212.

The previous prime is 81314792183. The next prime is 81314792263. The reversal of 81314792213 is 31229741318.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48742483729 + 32572308484 = 220777^2 + 180478^2 .

It is a cyclic number.

It is not a de Polignac number, because 81314792213 - 2¹⁰ = 81314791189 is a prime.

It is a super-2 number, since 2×81314792213² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81314792263) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40657396106 + 40657396107.

It is an arithmetic number, because the mean of its divisors is an integer number (40657396107).

Almost surely, 2^81314792213 is an apocalyptic number.

It is an amenable number.

81314792213 is a deficient number, since it is larger than the sum of its proper divisors (1).

81314792213 is an equidigital number, since it uses as much as digits as its factorization.

81314792213 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 41.

The spelling of 81314792213 in words is "eighty-one billion, three hundred fourteen million, seven hundred ninety-two thousand, two hundred thirteen".