180721228 has 24 divisors (see below), whose sum is σ = 319072320. Its totient is φ = 89562240.

The previous prime is 180721213. The next prime is 180721241. The reversal of 180721228 is 822127081.

It is a self number, because there is not a number n which added to its sum of digits gives 180721228.

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, 317328 + ... + 317896.

It is an arithmetic number, because the mean of its divisors is an integer number (13294680).

Almost surely, 2^180721228 is an apocalyptic number.

It is an amenable number.

180721228 is a deficient number, since it is larger than the sum of its proper divisors (138351092).

180721228 is a wasteful number, since it uses less digits than its factorization.

180721228 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1137 (or 1135 counting only the distinct ones).

The product of its (nonzero) digits is 3584, while the sum is 31.

The square root of 180721228 is about 13443.2595749692. The cubic root of 180721228 is about 565.3747251805.

The spelling of 180721228 in words is "one hundred eighty million, seven hundred twenty-one thousand, two hundred twenty-eight".