68072221 has 6 divisors (see below), whose sum is σ = 79186110. Its totient is φ = 58347576.

The previous prime is 68072197. The next prime is 68072237. The reversal of 68072221 is 12227086.

It can be written as a sum of positive squares in only one way, i.e., 51984100 + 16088121 = 7210^2 + 4011^2 .

It is not a de Polignac number, because 68072221 - 2⁵ = 68072189 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 68072221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68072021) by changing a digit.

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 5 ways as a sum of consecutive naturals, for example, 694566 + ... + 694663.

It is an arithmetic number, because the mean of its divisors is an integer number (13197685).

Almost surely, 2^68072221 is an apocalyptic number.

It is an amenable number.

68072221 is a deficient number, since it is larger than the sum of its proper divisors (11113889).

68072221 is a wasteful number, since it uses less digits than its factorization.

68072221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1389243 (or 1389236 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 28.

The square root of 68072221 is about 8250.5891304803. The cubic root of 68072221 is about 408.3099596598.

The spelling of 68072221 in words is "sixty-eight million, seventy-two thousand, two hundred twenty-one".