81116439337 has 2 divisors, whose sum is σ = 81116439338. Its totient is φ = 81116439336.

The previous prime is 81116439329. The next prime is 81116439343. The reversal of 81116439337 is 73393461118.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 77830398361 + 3286040976 = 278981^2 + 57324^2 .

It is a cyclic number.

It is not a de Polignac number, because 81116439337 - 2³ = 81116439329 is a prime.

It is not a weakly prime, because it can be changed into another prime (81116439637) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40558219668 + 40558219669.

It is an arithmetic number, because the mean of its divisors is an integer number (40558219669).

Almost surely, 2^81116439337 is an apocalyptic number.

It is an amenable number.

81116439337 is a deficient number, since it is larger than the sum of its proper divisors (1).

81116439337 is an equidigital number, since it uses as much as digits as its factorization.

81116439337 is an evil number, because the sum of its binary digits is even.

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

The spelling of 81116439337 in words is "eighty-one billion, one hundred sixteen million, four hundred thirty-nine thousand, three hundred thirty-seven".