81326081 has 4 divisors (see below), whose sum is σ = 81752064. Its totient is φ = 80900100.

The previous prime is 81326059. The next prime is 81326107. The reversal of 81326081 is 18062318.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81326081 - 2⁶ = 81326017 is a prime.

It is a super-2 number, since 2×81326081² = 13227862901637122, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81326041) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 212705 + ... + 213086.

It is an arithmetic number, because the mean of its divisors is an integer number (20438016).

Almost surely, 2^81326081 is an apocalyptic number.

It is an amenable number.

81326081 is a deficient number, since it is larger than the sum of its proper divisors (425983).

81326081 is a wasteful number, since it uses less digits than its factorization.

81326081 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425982.

The product of its (nonzero) digits is 2304, while the sum is 29.

The square root of 81326081 is about 9018.0974157524. The cubic root of 81326081 is about 433.2546988808.

Adding to 81326081 its reverse (18062318), we get a palindrome (99388399).

The spelling of 81326081 in words is "eighty-one million, three hundred twenty-six thousand, eighty-one".