81056317 has 2 divisors, whose sum is σ = 81056318. Its totient is φ = 81056316.

The previous prime is 81056309. The next prime is 81056329. The reversal of 81056317 is 71365018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 47485881 + 33570436 = 6891^2 + 5794^2 .

It is a cyclic number.

It is not a de Polignac number, because 81056317 - 2³ = 81056309 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81056917) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40528158 + 40528159.

It is an arithmetic number, because the mean of its divisors is an integer number (40528159).

Almost surely, 2^81056317 is an apocalyptic number.

It is an amenable number.

81056317 is a deficient number, since it is larger than the sum of its proper divisors (1).

81056317 is an equidigital number, since it uses as much as digits as its factorization.

81056317 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 5040, while the sum is 31.

The square root of 81056317 is about 9003.1281785833. The cubic root of 81056317 is about 432.7751233790.

The spelling of 81056317 in words is "eighty-one million, fifty-six thousand, three hundred seventeen".