81761601617 has 16 divisors (see below), whose sum is σ = 84948864000. Its totient is φ = 78599263680.

The previous prime is 81761601611. The next prime is 81761601619. The reversal of 81761601617 is 71610616718.

It is a cyclic number.

It is not a de Polignac number, because 81761601617 - 2⁴ = 81761601601 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81761601611) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17971259 + ... + 17975807.

It is an arithmetic number, because the mean of its divisors is an integer number (5309304000).

Almost surely, 2^81761601617 is an apocalyptic number.

It is an amenable number.

81761601617 is a deficient number, since it is larger than the sum of its proper divisors (3187262383).

81761601617 is a wasteful number, since it uses less digits than its factorization.

81761601617 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7136.

The product of its (nonzero) digits is 84672, while the sum is 44.

The spelling of 81761601617 in words is "eighty-one billion, seven hundred sixty-one million, six hundred one thousand, six hundred seventeen".