81087917 has 8 divisors (see below), whose sum is σ = 82043712. Its totient is φ = 80136000.

The previous prime is 81087913. The next prime is 81087947. The reversal of 81087917 is 71978018.

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 81087917 - 2² = 81087913 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (81087913) 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, 66917 + ... + 68117.

It is an arithmetic number, because the mean of its divisors is an integer number (10255464).

Almost surely, 2^81087917 is an apocalyptic number.

It is an amenable number.

81087917 is a deficient number, since it is larger than the sum of its proper divisors (955795).

81087917 is a wasteful number, since it uses less digits than its factorization.

81087917 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1939.

The product of its (nonzero) digits is 28224, while the sum is 41.

The square root of 81087917 is about 9004.8829531538. The cubic root of 81087917 is about 432.8313555462.

The spelling of 81087917 in words is "eighty-one million, eighty-seven thousand, nine hundred seventeen".