80666821 has 8 divisors (see below), whose sum is σ = 81872000. Its totient is φ = 79466400.

The previous prime is 80666809. The next prime is 80666851. The reversal of 80666821 is 12866608.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 80666821 - 2⁷ = 80666693 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 (80666801) 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 7 ways as a sum of consecutive naturals, for example, 46630 + ... + 48328.

It is an arithmetic number, because the mean of its divisors is an integer number (10234000).

Almost surely, 2^80666821 is an apocalyptic number.

It is an amenable number.

80666821 is a deficient number, since it is larger than the sum of its proper divisors (1205179).

80666821 is a wasteful number, since it uses less digits than its factorization.

80666821 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2379.

The product of its (nonzero) digits is 27648, while the sum is 37.

The square root of 80666821 is about 8981.4709819717. The cubic root of 80666821 is about 432.0808122853.

The spelling of 80666821 in words is "eighty million, six hundred sixty-six thousand, eight hundred twenty-one".