81072717 has 8 divisors (see below), whose sum is σ = 117924000. Its totient is φ = 49134960.

The previous prime is 81072713. The next prime is 81072731. The reversal of 81072717 is 71727018.

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

It is not a de Polignac number, because 81072717 - 2² = 81072713 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (33), and also a Moran number because the ratio is a prime number: 2456749 = 81072717 / (8 + 1 + 0 + 7 + 2 + 7 + 1 + 7).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81072713) 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, 1228342 + ... + 1228407.

It is an arithmetic number, because the mean of its divisors is an integer number (14740500).

Almost surely, 2^81072717 is an apocalyptic number.

It is an amenable number.

81072717 is a deficient number, since it is larger than the sum of its proper divisors (36851283).

81072717 is a wasteful number, since it uses less digits than its factorization.

81072717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2456763.

The product of its (nonzero) digits is 5488, while the sum is 33.

The square root of 81072717 is about 9004.0389270593. The cubic root of 81072717 is about 432.8043089858.

The spelling of 81072717 in words is "eighty-one million, seventy-two thousand, seven hundred seventeen".