81276865 has 16 divisors (see below), whose sum is σ = 99993600. Its totient is φ = 63391680.

The previous prime is 81276863. The next prime is 81276869. The reversal of 81276865 is 56867218.

It is not a de Polignac number, because 81276865 - 2¹ = 81276863 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81276863) 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 in 15 ways as a sum of consecutive naturals, for example, 81520 + ... + 82510.

It is an arithmetic number, because the mean of its divisors is an integer number (6249600).

Almost surely, 2^81276865 is an apocalyptic number.

It is an amenable number.

81276865 is a deficient number, since it is larger than the sum of its proper divisors (18716735).

81276865 is a wasteful number, since it uses less digits than its factorization.

81276865 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1392.

The product of its digits is 161280, while the sum is 43.

The square root of 81276865 is about 9015.3682675751. The cubic root of 81276865 is about 433.1672838482.

It can be divided in two parts, 812 and 76865, that added together give a palindrome (77677).

The spelling of 81276865 in words is "eighty-one million, two hundred seventy-six thousand, eight hundred sixty-five".