81317053 has 2 divisors, whose sum is σ = 81317054. Its totient is φ = 81317052.

The previous prime is 81317039. The next prime is 81317057. The reversal of 81317053 is 35071318.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 51308569 + 30008484 = 7163^2 + 5478^2 .

It is a cyclic number.

It is not a de Polignac number, because 81317053 - 2²⁵ = 47762621 is a prime.

It is a super-2 number, since 2×81317053² = 13224926217209618, which contains 22 as substring.

It is equal to p_4741903 and since 81317053 and 4741903 have the same sum of digits, it is a Honaker prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81317057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40658526 + 40658527.

It is an arithmetic number, because the mean of its divisors is an integer number (40658527).

Almost surely, 2^81317053 is an apocalyptic number.

It is an amenable number.

81317053 is a deficient number, since it is larger than the sum of its proper divisors (1).

81317053 is an equidigital number, since it uses as much as digits as its factorization.

81317053 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2520, while the sum is 28.

The square root of 81317053 is about 9017.5968528206. The cubic root of 81317053 is about 433.2386664341.

The spelling of 81317053 in words is "eighty-one million, three hundred seventeen thousand, fifty-three".