81066241 has 2 divisors, whose sum is σ = 81066242. Its totient is φ = 81066240.

The previous prime is 81066239. The next prime is 81066269. The reversal of 81066241 is 14266018.

It is an a-pointer prime, because the next prime (81066269) can be obtained adding 81066241 to its sum of digits (28).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 78694641 + 2371600 = 8871^2 + 1540^2 .

It is a cyclic number.

It is not a de Polignac number, because 81066241 - 2¹ = 81066239 is a prime.

Together with 81066239, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (81066221) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40533120 + 40533121.

It is an arithmetic number, because the mean of its divisors is an integer number (40533121).

Almost surely, 2^81066241 is an apocalyptic number.

It is an amenable number.

81066241 is a deficient number, since it is larger than the sum of its proper divisors (1).

81066241 is an equidigital number, since it uses as much as digits as its factorization.

81066241 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 2304, while the sum is 28.

The square root of 81066241 is about 9003.6793034848. The cubic root of 81066241 is about 432.7927847006.

The spelling of 81066241 in words is "eighty-one million, sixty-six thousand, two hundred forty-one".