81713568289 has 4 divisors (see below), whose sum is σ = 81839865024. Its totient is φ = 81587271556.

The previous prime is 81713568283. The next prime is 81713568317. The reversal of 81713568289 is 98286531718.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 81713568289 - 2³ = 81713568281 is a prime.

It is a super-3 number, since 3×81713568289³ (a number of 34 digits) contains 333 as substring.

It is a Smith number, since the sum of its digits (58) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81713568281) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 63147397 + ... + 63148690.

It is an arithmetic number, because the mean of its divisors is an integer number (20459966256).

Almost surely, 2^81713568289 is an apocalyptic number.

It is an amenable number.

81713568289 is a deficient number, since it is larger than the sum of its proper divisors (126296735).

81713568289 is a wasteful number, since it uses less digits than its factorization.

81713568289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 126296734.

The product of its digits is 5806080, while the sum is 58.

The spelling of 81713568289 in words is "eighty-one billion, seven hundred thirteen million, five hundred sixty-eight thousand, two hundred eighty-nine".