68216281 has 12 divisors (see below), whose sum is σ = 79677108. Its totient is φ = 58232832.

The previous prime is 68216279. The next prime is 68216293. The reversal of 68216281 is 18261286.

It can be written as a sum of positive squares in 2 ways, for example, as 39690000 + 28526281 = 6300^2 + 5341^2 .

It is not a de Polignac number, because 68216281 - 2¹ = 68216279 is a prime.

It is a super-2 number, since 2×68216281² = 9306921986941922, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68216201) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 9885 + ... + 15301.

It is an arithmetic number, because the mean of its divisors is an integer number (6639759).

Almost surely, 2^68216281 is an apocalyptic number.

It is an amenable number.

68216281 is a deficient number, since it is larger than the sum of its proper divisors (11460827).

68216281 is a wasteful number, since it uses less digits than its factorization.

68216281 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5688 (or 5681 counting only the distinct ones).

The product of its digits is 9216, while the sum is 34.

The square root of 68216281 is about 8259.3148020886. The cubic root of 68216281 is about 408.5977896861.

The spelling of 68216281 in words is "sixty-eight million, two hundred sixteen thousand, two hundred eighty-one".