80728520069 has 4 divisors (see below), whose sum is σ = 81084152544. Its totient is φ = 80372887596.

The previous prime is 80728520057. The next prime is 80728520071. The reversal of 80728520069 is 96002582708.

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 80728520069 - 2⁴ = 80728520053 is a prime.

It is a super-2 number, since 2×80728520069² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80728520099) 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, 177815897 + ... + 177816350.

It is an arithmetic number, because the mean of its divisors is an integer number (20271038136).

Almost surely, 2^80728520069 is an apocalyptic number.

It is an amenable number.

80728520069 is a deficient number, since it is larger than the sum of its proper divisors (355632475).

80728520069 is a wasteful number, since it uses less digits than its factorization.

80728520069 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 355632474.

The product of its (nonzero) digits is 483840, while the sum is 47.

The spelling of 80728520069 in words is "eighty billion, seven hundred twenty-eight million, five hundred twenty thousand, sixty-nine".