81317323 has 2 divisors, whose sum is σ = 81317324. Its totient is φ = 81317322.

The previous prime is 81317303. The next prime is 81317329. The reversal of 81317323 is 32371318.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 81317323 - 2¹³ = 81309131 is a prime.

It is a super-2 number, since 2×81317323² = 13225014039772658, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81317291 and 81317300.

It is not a weakly prime, because it can be changed into another prime (81317329) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40658661 + 40658662.

It is an arithmetic number, because the mean of its divisors is an integer number (40658662).

Almost surely, 2^81317323 is an apocalyptic number.

81317323 is a deficient number, since it is larger than the sum of its proper divisors (1).

81317323 is an equidigital number, since it uses as much as digits as its factorization.

81317323 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3024, while the sum is 28.

The square root of 81317323 is about 9017.6118235373. The cubic root of 81317323 is about 433.2391459330.

The spelling of 81317323 in words is "eighty-one million, three hundred seventeen thousand, three hundred twenty-three".