68688221 has 4 divisors (see below), whose sum is σ = 78500832. Its totient is φ = 58875612.

The previous prime is 68688149. The next prime is 68688223. The reversal of 68688221 is 12288686.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 68688221 - 2¹⁰ = 68687197 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68688223) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 4906295 + ... + 4906308.

It is an arithmetic number, because the mean of its divisors is an integer number (19625208).

Almost surely, 2^68688221 is an apocalyptic number.

It is an amenable number.

68688221 is a deficient number, since it is larger than the sum of its proper divisors (9812611).

68688221 is an equidigital number, since it uses as much as digits as its factorization.

68688221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9812610.

The product of its digits is 73728, while the sum is 41.

The square root of 68688221 is about 8287.8357247233. The cubic root of 68688221 is about 409.5378910146.

The spelling of 68688221 in words is "sixty-eight million, six hundred eighty-eight thousand, two hundred twenty-one".