81401611 has 2 divisors, whose sum is σ = 81401612. Its totient is φ = 81401610.

The previous prime is 81401609. The next prime is 81401647. The reversal of 81401611 is 11610418.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81401611 - 2¹ = 81401609 is a prime.

Together with 81401609, it forms a pair of twin primes.

It is not a weakly prime, because it can be changed into another prime (81701611) 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, 40700805 + 40700806.

It is an arithmetic number, because the mean of its divisors is an integer number (40700806).

Almost surely, 2^81401611 is an apocalyptic number.

81401611 is a deficient number, since it is larger than the sum of its proper divisors (1).

81401611 is an equidigital number, since it uses as much as digits as its factorization.

81401611 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 192, while the sum is 22.

The square root of 81401611 is about 9022.2841342977. The cubic root of 81401611 is about 433.3887829766.

The spelling of 81401611 in words is "eighty-one million, four hundred one thousand, six hundred eleven".