81581716603 has 8 divisors (see below), whose sum is σ = 83416486400. Its totient is φ = 79766999208.

The previous prime is 81581716597. The next prime is 81581716613. The reversal of 81581716603 is 30661718518.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-81581716603 is a prime.

It is not an unprimeable number, because it can be changed into a prime (81581716613) 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, 5004873 + ... + 5021146.

It is an arithmetic number, because the mean of its divisors is an integer number (10427060800).

Almost surely, 2^81581716603 is an apocalyptic number.

81581716603 is a deficient number, since it is larger than the sum of its proper divisors (1834769797).

81581716603 is a wasteful number, since it uses less digits than its factorization.

81581716603 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10026201.

The product of its (nonzero) digits is 241920, while the sum is 46.

The spelling of 81581716603 in words is "eighty-one billion, five hundred eighty-one million, seven hundred sixteen thousand, six hundred three".