81746007181 has 2 divisors, whose sum is σ = 81746007182. Its totient is φ = 81746007180.

The previous prime is 81746007139. The next prime is 81746007263. The reversal of 81746007181 is 18170064718.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 71044104681 + 10701902500 = 266541^2 + 103450^2 .

It is a cyclic number.

It is not a de Polignac number, because 81746007181 - 2¹³ = 81745998989 is a prime.

It is a super-2 number, since 2×81746007181² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81746007131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40873003590 + 40873003591.

It is an arithmetic number, because the mean of its divisors is an integer number (40873003591).

Almost surely, 2^81746007181 is an apocalyptic number.

It is an amenable number.

81746007181 is a deficient number, since it is larger than the sum of its proper divisors (1).

81746007181 is an equidigital number, since it uses as much as digits as its factorization.

81746007181 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 75264, while the sum is 43.

The spelling of 81746007181 in words is "eighty-one billion, seven hundred forty-six million, seven thousand, one hundred eighty-one".