80721779044 has 6 divisors (see below), whose sum is σ = 141263113334. Its totient is φ = 40360889520.

The previous prime is 80721779029. The next prime is 80721779057. The reversal of 80721779044 is 44097712708.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 58437260644 + 22284518400 = 241738^2 + 149280^2 .

It is a super-2 number, since 2×80721779044² (a number of 23 digits) contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10090222377 + ... + 10090222384.

Almost surely, 2^80721779044 is an apocalyptic number.

It is an amenable number.

80721779044 is a deficient number, since it is larger than the sum of its proper divisors (60541334290).

80721779044 is a wasteful number, since it uses less digits than its factorization.

80721779044 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20180444765 (or 20180444763 counting only the distinct ones).

The product of its (nonzero) digits is 790272, while the sum is 49.

The spelling of 80721779044 in words is "eighty billion, seven hundred twenty-one million, seven hundred seventy-nine thousand, forty-four".