81377017 has 2 divisors, whose sum is σ = 81377018. Its totient is φ = 81377016.

The previous prime is 81376993. The next prime is 81377029. The reversal of 81377017 is 71077318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 42302016 + 39075001 = 6504^2 + 6251^2 .

It is a cyclic number.

It is not a de Polignac number, because 81377017 - 2¹⁹ = 80852729 is a prime.

It is not a weakly prime, because it can be changed into another prime (81377047) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40688508 + 40688509.

It is an arithmetic number, because the mean of its divisors is an integer number (40688509).

Almost surely, 2^81377017 is an apocalyptic number.

It is an amenable number.

81377017 is a deficient number, since it is larger than the sum of its proper divisors (1).

81377017 is an equidigital number, since it uses as much as digits as its factorization.

81377017 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8232, while the sum is 34.

The square root of 81377017 is about 9020.9210727065. The cubic root of 81377017 is about 433.3451317629.

The spelling of 81377017 in words is "eighty-one million, three hundred seventy-seven thousand, seventeen".