81677317 has 2 divisors, whose sum is σ = 81677318. Its totient is φ = 81677316.

The previous prime is 81677303. The next prime is 81677329. The reversal of 81677317 is 71377618.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 61481281 + 20196036 = 7841^2 + 4494^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81677317 is a prime.

It is a super-2 number, since 2×81677317² = 13342368224636978, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 81677317.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81677377) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40838658 + 40838659.

It is an arithmetic number, because the mean of its divisors is an integer number (40838659).

Almost surely, 2^81677317 is an apocalyptic number.

It is an amenable number.

81677317 is a deficient number, since it is larger than the sum of its proper divisors (1).

81677317 is an equidigital number, since it uses as much as digits as its factorization.

81677317 is an evil number, because the sum of its binary digits is even.

The product of its digits is 49392, while the sum is 40.

The square root of 81677317 is about 9037.5503871348. The cubic root of 81677317 is about 433.8775253098.

The spelling of 81677317 in words is "eighty-one million, six hundred seventy-seven thousand, three hundred seventeen".