80490805821 has 6 divisors (see below), whose sum is σ = 116264497310. Its totient is φ = 53660537208.

The previous prime is 80490805799. The next prime is 80490805823. The reversal of 80490805821 is 12850809408.

It is a happy number.

80490805821 is a `hidden beast` number, since 8 + 0 + 490 + 80 + 5 + 82 + 1 = 666.

It can be written as a sum of positive squares in only one way, i.e., 62938265625 + 17552540196 = 250875^2 + 132486^2 .

It is not a de Polignac number, because 80490805821 - 2⁶ = 80490805757 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80490805823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4471711426 + ... + 4471711443.

Almost surely, 2^80490805821 is an apocalyptic number.

It is an amenable number.

80490805821 is a deficient number, since it is larger than the sum of its proper divisors (35773691489).

80490805821 is a wasteful number, since it uses less digits than its factorization.

80490805821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8943422875 (or 8943422872 counting only the distinct ones).

The product of its (nonzero) digits is 184320, while the sum is 45.

The spelling of 80490805821 in words is "eighty billion, four hundred ninety million, eight hundred five thousand, eight hundred twenty-one".