81705702 has 64 divisors (see below), whose sum is σ = 186701760. Its totient is φ = 23654400.

The previous prime is 81705691. The next prime is 81705703. The reversal of 81705702 is 20750718.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 81705702.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81705703) 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 31 ways as a sum of consecutive naturals, for example, 92302 + ... + 93182.

It is an arithmetic number, because the mean of its divisors is an integer number (2917215).

Almost surely, 2^81705702 is an apocalyptic number.

81705702 is a gapful number since it is divisible by the number (82) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 81705702, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93350880).

81705702 is an abundant number, since it is smaller than the sum of its proper divisors (104996058).

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

81705702 is a wasteful number, since it uses less digits than its factorization.

81705702 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 969.

The product of its (nonzero) digits is 3920, while the sum is 30.

The square root of 81705702 is about 9039.1206430714. The cubic root of 81705702 is about 433.9277807443.

The spelling of 81705702 in words is "eighty-one million, seven hundred five thousand, seven hundred two".