81712541 has 2 divisors, whose sum is σ = 81712542. Its totient is φ = 81712540.

The previous prime is 81712531. The next prime is 81712567. The reversal of 81712541 is 14521718.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 55190041 + 26522500 = 7429^2 + 5150^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81712541 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81712531) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40856270 + 40856271.

It is an arithmetic number, because the mean of its divisors is an integer number (40856271).

Almost surely, 2^81712541 is an apocalyptic number.

It is an amenable number.

81712541 is a deficient number, since it is larger than the sum of its proper divisors (1).

81712541 is an equidigital number, since it uses as much as digits as its factorization.

81712541 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2240, while the sum is 29.

The square root of 81712541 is about 9039.4989352287. The cubic root of 81712541 is about 433.9398874037.

The spelling of 81712541 in words is "eighty-one million, seven hundred twelve thousand, five hundred forty-one".