81705122 has 8 divisors (see below), whose sum is σ = 126783900. Its totient is φ = 39443824.

The previous prime is 81705121. The next prime is 81705133. The reversal of 81705122 is 22150718.

It can be written as a sum of positive squares in 2 ways, for example, as 75359761 + 6345361 = 8681^2 + 2519^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a super-3 number, since 3×81705122³ (a number of 25 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a junction number, because it is equal to n+sod(n) for n = 81705091 and 81705100.

It is not an unprimeable number, because it can be changed into a prime (81705121) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 704297 + ... + 704412.

Almost surely, 2^81705122 is an apocalyptic number.

81705122 is a deficient number, since it is larger than the sum of its proper divisors (45078778).

81705122 is a wasteful number, since it uses less digits than its factorization.

81705122 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1408740.

The product of its (nonzero) digits is 1120, while the sum is 26.

The square root of 81705122 is about 9039.0885602477. The cubic root of 81705122 is about 433.9267539751.

The spelling of 81705122 in words is "eighty-one million, seven hundred five thousand, one hundred twenty-two".