221682320 has 40 divisors (see below), whose sum is σ = 516034680. Its totient is φ = 88565760.

The previous prime is 221682319. The next prime is 221682341. The reversal of 221682320 is 23286122.

It is a Cunningham number, because it is equal to 14889²-1.

It can be written as a sum of positive squares in 4 ways, for example, as 9339136 + 212343184 = 3056^2 + 14572^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a self number, because there is not a number n which added to its sum of digits gives 221682320.

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, 118190 + ... + 120050.

It is an arithmetic number, because the mean of its divisors is an integer number (12900867).

Almost surely, 2^221682320 is an apocalyptic number.

221682320 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

221682320 is an abundant number, since it is smaller than the sum of its proper divisors (294352360).

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

221682320 is a wasteful number, since it uses less digits than its factorization.

221682320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3363 (or 3357 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 26.

The square root of 221682320 is about 14888.9999664182. Note that the first 4 decimals coincide. The cubic root of 221682320 is about 605.2159327569.

The spelling of 221682320 in words is "two hundred twenty-one million, six hundred eighty-two thousand, three hundred twenty".