68544221 has 8 divisors (see below), whose sum is σ = 72649080. Its totient is φ = 64447488.

The previous prime is 68544167. The next prime is 68544263. The reversal of 68544221 is 12244586.

It can be written as a sum of positive squares in 4 ways, for example, as 4368100 + 64176121 = 2090^2 + 8011^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-68544221 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68544121) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 29075 + ... + 31343.

It is an arithmetic number, because the mean of its divisors is an integer number (9081135).

Almost surely, 2^68544221 is an apocalyptic number.

It is an amenable number.

68544221 is a deficient number, since it is larger than the sum of its proper divisors (4104859).

68544221 is a wasteful number, since it uses less digits than its factorization.

68544221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4063.

The product of its digits is 15360, while the sum is 32.

The square root of 68544221 is about 8279.1437359186. The cubic root of 68544221 is about 409.2515017097.

The spelling of 68544221 in words is "sixty-eight million, five hundred forty-four thousand, two hundred twenty-one".