21282180 has 24 divisors (see below), whose sum is σ = 59590272. Its totient is φ = 5675232.

The previous prime is 21282167. The next prime is 21282197. The reversal of 21282180 is 8128212.

It is a self number, because there is not a number n which added to its sum of digits gives 21282180.

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 177292 + ... + 177411.

It is an arithmetic number, because the mean of its divisors is an integer number (2482928).

Almost surely, 2^21282180 is an apocalyptic number.

21282180 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21282180 is an abundant number, since it is smaller than the sum of its proper divisors (38308092).

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

21282180 is a wasteful number, since it uses less digits than its factorization.

21282180 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 354715 (or 354713 counting only the distinct ones).

The product of its (nonzero) digits is 512, while the sum is 24.

The square root of 21282180 is about 4613.2613192838. The cubic root of 21282180 is about 277.1226589494.

The spelling of 21282180 in words is "twenty-one million, two hundred eighty-two thousand, one hundred eighty".