81313311331387 has 2 divisors, whose sum is σ = 81313311331388. Its totient is φ = 81313311331386.

The previous prime is 81313311331249. The next prime is 81313311331411. The reversal of 81313311331387 is 78313311331318.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81313311331387 - 2¹⁵ = 81313311298619 is a prime.

It is a super-2 number, since 2×81313311331387² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (81313311331487) 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, 40656655665693 + 40656655665694.

It is an arithmetic number, because the mean of its divisors is an integer number (40656655665694).

Almost surely, 2^{81313311331387} is an apocalyptic number.

81313311331387 is a deficient number, since it is larger than the sum of its proper divisors (1).

81313311331387 is an equidigital number, since it uses as much as digits as its factorization.

81313311331387 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 326592, while the sum is 46.

The spelling of 81313311331387 in words is "eighty-one trillion, three hundred thirteen billion, three hundred eleven million, three hundred thirty-one thousand, three hundred eighty-seven".