81704160 has 96 divisors (see below), whose sum is σ = 285979680. Its totient is φ = 21786624.

The previous prime is 81704153. The next prime is 81704191. The reversal of 81704160 is 6140718.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (96).

It is a super-2 number, since 2×81704160² = 13351139522611200, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 5137 + ... + 13776.

It is an arithmetic number, because the mean of its divisors is an integer number (2978955).

Almost surely, 2^81704160 is an apocalyptic number.

81704160 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

81704160 is an abundant number, since it is smaller than the sum of its proper divisors (204275520).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

81704160 is a wasteful number, since it uses less digits than its factorization.

81704160 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18937 (or 18923 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 27.

The square root of 81704160 is about 9039.0353467613. The cubic root of 81704160 is about 433.9250509436.

Adding to 81704160 its reverse (6140718), we get a palindrome (87844878).

The spelling of 81704160 in words is "eighty-one million, seven hundred four thousand, one hundred sixty".