80998945565 has 4 divisors (see below), whose sum is σ = 97198734684. Its totient is φ = 64799156448.

The previous prime is 80998945561. The next prime is 80998945579. The reversal of 80998945565 is 56554989908.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20909738404 + 60089207161 = 144602^2 + 245131^2 .

It is a cyclic number.

It is not a de Polignac number, because 80998945565 - 2² = 80998945561 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 80998945495 and 80998945504.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80998945561) 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, 8099894552 + ... + 8099894561.

It is an arithmetic number, because the mean of its divisors is an integer number (24299683671).

Almost surely, 2^80998945565 is an apocalyptic number.

It is an amenable number.

80998945565 is a deficient number, since it is larger than the sum of its proper divisors (16199789119).

80998945565 is a wasteful number, since it uses less digits than its factorization.

80998945565 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16199789118.

The product of its (nonzero) digits is 139968000, while the sum is 68.

The spelling of 80998945565 in words is "eighty billion, nine hundred ninety-eight million, nine hundred forty-five thousand, five hundred sixty-five".