81706900 has 36 divisors (see below), whose sum is σ = 193425120. Its totient is φ = 29711200.

The previous prime is 81706861. The next prime is 81706901. The reversal of 81706900 is 960718.

It is a super-2 number, since 2×81706900² = 13352035015220000, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81706901) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 36040 + ... + 38239.

It is an arithmetic number, because the mean of its divisors is an integer number (5372920).

Almost surely, 2^81706900 is an apocalyptic number.

It is an amenable number.

81706900 is an abundant number, since it is smaller than the sum of its proper divisors (111718220).

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

81706900 is a wasteful number, since it uses less digits than its factorization.

81706900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 74304 (or 74297 counting only the distinct ones).

The product of its (nonzero) digits is 3024, while the sum is 31.

The square root of 81706900 is about 9039.1869103366. The cubic root of 81706900 is about 433.9299015385.

The spelling of 81706900 in words is "eighty-one million, seven hundred six thousand, nine hundred".