81223980 has 24 divisors (see below), whose sum is σ = 227427312. Its totient is φ = 21659712.

The previous prime is 81223969. The next prime is 81223997. The reversal of 81223980 is 8932218.

It is an unprimeable number.

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, 676807 + ... + 676926.

It is an arithmetic number, because the mean of its divisors is an integer number (9476138).

Almost surely, 2^81223980 is an apocalyptic number.

It is an amenable number.

81223980 is an abundant number, since it is smaller than the sum of its proper divisors (146203332).

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

81223980 is a wasteful number, since it uses less digits than its factorization.

81223980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1353745 (or 1353743 counting only the distinct ones).

The product of its (nonzero) digits is 6912, while the sum is 33.

The square root of 81223980 is about 9012.4347431757. The cubic root of 81223980 is about 433.0733127771.

The spelling of 81223980 in words is "eighty-one million, two hundred twenty-three thousand, nine hundred eighty".