81427816 has 32 divisors (see below), whose sum is σ = 155325600. Its totient is φ = 40014400.

The previous prime is 81427799. The next prime is 81427817. The reversal of 81427816 is 61872418.

It is not an unprimeable number, because it can be changed into a prime (81427817) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 144351 + ... + 144913.

It is an arithmetic number, because the mean of its divisors is an integer number (4853925).

Almost surely, 2^81427816 is an apocalyptic number.

It is an amenable number.

81427816 is a deficient number, since it is larger than the sum of its proper divisors (73897784).

81427816 is a wasteful number, since it uses less digits than its factorization.

81427816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 849 (or 845 counting only the distinct ones).

The product of its digits is 21504, while the sum is 37.

The square root of 81427816 is about 9023.7362550110. The cubic root of 81427816 is about 433.4352838360.

The spelling of 81427816 in words is "eighty-one million, four hundred twenty-seven thousand, eight hundred sixteen".