81705473 has 2 divisors, whose sum is σ = 81705474. Its totient is φ = 81705472.

The previous prime is 81705467. The next prime is 81705479. The reversal of 81705473 is 37450718.

It is a balanced prime because it is at equal distance from previous prime (81705467) and next prime (81705479).

It can be written as a sum of positive squares in only one way, i.e., 72114064 + 9591409 = 8492^2 + 3097^2 .

It is a cyclic number.

It is not a de Polignac number, because 81705473 - 2⁴ = 81705457 is a prime.

It is not a weakly prime, because it can be changed into another prime (81705479) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40852736 + 40852737.

It is an arithmetic number, because the mean of its divisors is an integer number (40852737).

Almost surely, 2^81705473 is an apocalyptic number.

It is an amenable number.

81705473 is a deficient number, since it is larger than the sum of its proper divisors (1).

81705473 is an equidigital number, since it uses as much as digits as its factorization.

81705473 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 23520, while the sum is 35.

The square root of 81705473 is about 9039.1079759012. The cubic root of 81705473 is about 433.9273753481.

The spelling of 81705473 in words is "eighty-one million, seven hundred five thousand, four hundred seventy-three".