80821005 has 16 divisors (see below), whose sum is σ = 129467904. Its totient is φ = 43053120.

The previous prime is 80820991. The next prime is 80821007. The reversal of 80821005 is 50012808.

It is not a de Polignac number, because 80821005 - 2¹⁶ = 80755469 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (80821007) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 12147 + ... + 17583.

It is an arithmetic number, because the mean of its divisors is an integer number (8091744).

Almost surely, 2^80821005 is an apocalyptic number.

It is an amenable number.

80821005 is a deficient number, since it is larger than the sum of its proper divisors (48646899).

80821005 is a wasteful number, since it uses less digits than its factorization.

80821005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6436.

The product of its (nonzero) digits is 640, while the sum is 24.

The square root of 80821005 is about 8990.0503335632. The cubic root of 80821005 is about 432.3559255932.

The spelling of 80821005 in words is "eighty million, eight hundred twenty-one thousand, five".