81281708 has 6 divisors (see below), whose sum is σ = 142242996. Its totient is φ = 40640852.

The previous prime is 81281687. The next prime is 81281713. The reversal of 81281708 is 80718218.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 10160210 + ... + 10160217.

It is an arithmetic number, because the mean of its divisors is an integer number (23707166).

Almost surely, 2^81281708 is an apocalyptic number.

It is an amenable number.

81281708 is a deficient number, since it is larger than the sum of its proper divisors (60961288).

81281708 is a wasteful number, since it uses less digits than its factorization.

81281708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20320431 (or 20320429 counting only the distinct ones).

The product of its (nonzero) digits is 7168, while the sum is 35.

The square root of 81281708 is about 9015.6368604775. The cubic root of 81281708 is about 433.1758873112.

The spelling of 81281708 in words is "eighty-one million, two hundred eighty-one thousand, seven hundred eight".