80921800 has 48 divisors (see below), whose sum is σ = 188799300. Its totient is φ = 32256000.

The previous prime is 80921777. The next prime is 80921809. The reversal of 80921800 is 812908.

It can be written as a sum of positive squares in 6 ways, for example, as 48636676 + 32285124 = 6974^2 + 5682^2 .

It is not an unprimeable number, because it can be changed into a prime (80921809) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 79696 + ... + 80704.

Almost surely, 2^80921800 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 80921800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94399650).

80921800 is an abundant number, since it is smaller than the sum of its proper divisors (107877500).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

80921800 is a wasteful number, since it uses less digits than its factorization.

80921800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1426 (or 1417 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 28.

The square root of 80921800 is about 8995.6545064826. The cubic root of 80921800 is about 432.5355868565.

The spelling of 80921800 in words is "eighty million, nine hundred twenty-one thousand, eight hundred".