81120617 has 8 divisors (see below), whose sum is σ = 86169096. Its totient is φ = 76102912.

The previous prime is 81120607. The next prime is 81120643. The reversal of 81120617 is 71602118.

It can be written as a sum of positive squares in 4 ways, for example, as 22429696 + 58690921 = 4736^2 + 7661^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 81120617 - 2⁴ = 81120601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81120607) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2138 + ... + 12915.

It is an arithmetic number, because the mean of its divisors is an integer number (10771137).

Almost surely, 2^81120617 is an apocalyptic number.

It is an amenable number.

81120617 is a deficient number, since it is larger than the sum of its proper divisors (5048479).

81120617 is a wasteful number, since it uses less digits than its factorization.

81120617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15387.

The product of its (nonzero) digits is 672, while the sum is 26.

The square root of 81120617 is about 9006.6984517080. The cubic root of 81120617 is about 432.8895297836.

The spelling of 81120617 in words is "eighty-one million, one hundred twenty thousand, six hundred seventeen".