81230715689 has 8 divisors (see below), whose sum is σ = 82774082952. Its totient is φ = 79687745280.

The previous prime is 81230715667. The next prime is 81230715701. The reversal of 81230715689 is 98651703218.

It can be written as a sum of positive squares in 4 ways, for example, as 58283616400 + 22947099289 = 241420^2 + 151483^2 .

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 81230715689 - 2¹² = 81230711593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81230715619) 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, 331649 + ... + 521969.

It is an arithmetic number, because the mean of its divisors is an integer number (10346760369).

Almost surely, 2^81230715689 is an apocalyptic number.

It is an amenable number.

81230715689 is a deficient number, since it is larger than the sum of its proper divisors (1543367263).

81230715689 is a wasteful number, since it uses less digits than its factorization.

81230715689 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 198427.

The product of its (nonzero) digits is 725760, while the sum is 50.

The spelling of 81230715689 in words is "eighty-one billion, two hundred thirty million, seven hundred fifteen thousand, six hundred eighty-nine".