81101 has 2 divisors, whose sum is σ = 81102. Its totient is φ = 81100.

The previous prime is 81097. The next prime is 81119. The reversal of 81101 is 10118.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75625 + 5476 = 275^2 + 74^2 .

It is a cyclic number.

It is not a de Polignac number, because 81101 - 2² = 81097 is a prime.

It is a plaindrome in base 16.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40550 + 40551.

It is an arithmetic number, because the mean of its divisors is an integer number (40551).

2⁸¹¹⁰¹ is an apocalyptic number.

It is an amenable number.

81101 is a deficient number, since it is larger than the sum of its proper divisors (1).

81101 is an equidigital number, since it uses as much as digits as its factorization.

81101 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8, while the sum is 11.

The square root of 81101 is about 284.7823730500. The cubic root of 81101 is about 43.2854632455.

Adding to 81101 its reverse (10118), we get a palindrome (91219).

The spelling of 81101 in words is "eighty-one thousand, one hundred one".