81286181 has 4 divisors (see below), whose sum is σ = 82315200. Its totient is φ = 80257164.

The previous prime is 81286087. The next prime is 81286189. The reversal of 81286181 is 18168218.

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 81286181 - 2¹⁰ = 81285157 is a prime.

It is a super-2 number, since 2×81286181² = 13214886443129522, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81286189) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 514391 + ... + 514548.

It is an arithmetic number, because the mean of its divisors is an integer number (20578800).

Almost surely, 2^81286181 is an apocalyptic number.

It is an amenable number.

81286181 is a deficient number, since it is larger than the sum of its proper divisors (1029019).

81286181 is a wasteful number, since it uses less digits than its factorization.

81286181 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1029018.

The product of its digits is 6144, while the sum is 35.

The square root of 81286181 is about 9015.8849260624. The cubic root of 81286181 is about 433.1838331752.

The spelling of 81286181 in words is "eighty-one million, two hundred eighty-six thousand, one hundred eighty-one".