81108031 has 2 divisors, whose sum is σ = 81108032. Its totient is φ = 81108030.

The previous prime is 81108023. The next prime is 81108043. The reversal of 81108031 is 13080118.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 81108031 - 2³ = 81108023 is a prime.

It is a super-2 number, since 2×81108031² = 13157025385393922, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 81107993 and 81108011.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (81108631) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40554015 + 40554016.

It is an arithmetic number, because the mean of its divisors is an integer number (40554016).

Almost surely, 2^81108031 is an apocalyptic number.

81108031 is a deficient number, since it is larger than the sum of its proper divisors (1).

81108031 is an equidigital number, since it uses as much as digits as its factorization.

81108031 is an evil number, because the sum of its binary digits is even.

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

The square root of 81108031 is about 9005.9997224073. Note that the first 3 decimals coincide. The cubic root of 81108031 is about 432.8671407797.

Adding to 81108031 its reverse (13080118), we get a palindrome (94188149).

The spelling of 81108031 in words is "eighty-one million, one hundred eight thousand, thirty-one".