68817721 has 8 divisors (see below), whose sum is σ = 80567424. Its totient is φ = 57547680.

The previous prime is 68817713. The next prime is 68817731. The reversal of 68817721 is 12771886.

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

It is a cyclic number.

It is not a de Polignac number, because 68817721 - 2³ = 68817713 is a prime.

It is not an unprimeable number, because it can be changed into a prime (68817701) 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 7 ways as a sum of consecutive naturals, for example, 119605 + ... + 120178.

It is an arithmetic number, because the mean of its divisors is an integer number (10070928).

Almost surely, 2^68817721 is an apocalyptic number.

It is an amenable number.

68817721 is a deficient number, since it is larger than the sum of its proper divisors (11749703).

68817721 is a wasteful number, since it uses less digits than its factorization.

68817721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 239831.

The product of its digits is 37632, while the sum is 40.

The square root of 68817721 is about 8295.6447006848. The cubic root of 68817721 is about 409.7951008699.

The spelling of 68817721 in words is "sixty-eight million, eight hundred seventeen thousand, seven hundred twenty-one".