81671704 has 8 divisors (see below), whose sum is σ = 153134460. Its totient is φ = 40835848.

The previous prime is 81671683. The next prime is 81671729. The reversal of 81671704 is 40717618.

It is a tau number, because it is divible by the number of its divisors (8).

It is a self number, because there is not a number n which added to its sum of digits gives 81671704.

It is a congruent number.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 5104474 + ... + 5104489.

Almost surely, 2^81671704 is an apocalyptic number.

It is an amenable number.

81671704 is a deficient number, since it is larger than the sum of its proper divisors (71462756).

81671704 is a wasteful number, since it uses less digits than its factorization.

81671704 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10208969 (or 10208965 counting only the distinct ones).

The product of its (nonzero) digits is 9408, while the sum is 34.

The square root of 81671704 is about 9037.2398441117. The cubic root of 81671704 is about 433.8675861556.

The spelling of 81671704 in words is "eighty-one million, six hundred seventy-one thousand, seven hundred four".