81680425609 has 8 divisors (see below), whose sum is σ = 84319252992. Its totient is φ = 79041846720.

The previous prime is 81680425591. The next prime is 81680425661. The reversal of 81680425609 is 90652408618.

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 81680425609 - 2⁹ = 81680425097 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (81680425679) 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, 792897 + ... + 889969.

It is an arithmetic number, because the mean of its divisors is an integer number (10539906624).

Almost surely, 2^81680425609 is an apocalyptic number.

It is an amenable number.

81680425609 is a deficient number, since it is larger than the sum of its proper divisors (2638827383).

81680425609 is a wasteful number, since it uses less digits than its factorization.

81680425609 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 124247.

The product of its (nonzero) digits is 829440, while the sum is 49.

The spelling of 81680425609 in words is "eighty-one billion, six hundred eighty million, four hundred twenty-five thousand, six hundred nine".