81053681 has 2 divisors, whose sum is σ = 81053682. Its totient is φ = 81053680.

The previous prime is 81053653. The next prime is 81053683. The reversal of 81053681 is 18635018.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 75968656 + 5085025 = 8716^2 + 2255^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81053681 is a prime.

It is a super-2 number, since 2×81053681² = 13139398407299522, which contains 22 as substring.

Together with 81053683, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (81053683) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40526840 + 40526841.

It is an arithmetic number, because the mean of its divisors is an integer number (40526841).

Almost surely, 2^81053681 is an apocalyptic number.

It is an amenable number.

81053681 is a deficient number, since it is larger than the sum of its proper divisors (1).

81053681 is an equidigital number, since it uses as much as digits as its factorization.

81053681 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5760, while the sum is 32.

The square root of 81053681 is about 9002.9817838314. The cubic root of 81053681 is about 432.7704319593.

Adding to 81053681 its reverse (18635018), we get a palindrome (99688699).

The spelling of 81053681 in words is "eighty-one million, fifty-three thousand, six hundred eighty-one".