68721361 has 4 divisors (see below), whose sum is σ = 72763812. Its totient is φ = 64678912.

The previous prime is 68721313. The next prime is 68721383. The reversal of 68721361 is 16312786.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 41525136 + 27196225 = 6444^2 + 5215^2 .

It is a cyclic number.

It is not a de Polignac number, because 68721361 - 2¹⁵ = 68688593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68721061) 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, 2021200 + ... + 2021233.

It is an arithmetic number, because the mean of its divisors is an integer number (18190953).

Almost surely, 2^68721361 is an apocalyptic number.

It is an amenable number.

68721361 is a deficient number, since it is larger than the sum of its proper divisors (4042451).

68721361 is a wasteful number, since it uses less digits than its factorization.

68721361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4042450.

The product of its digits is 12096, while the sum is 34.

The square root of 68721361 is about 8289.8347993190. The cubic root of 68721361 is about 409.6037436620.

The spelling of 68721361 in words is "sixty-eight million, seven hundred twenty-one thousand, three hundred sixty-one".