68518481 has 4 divisors (see below), whose sum is σ = 68537700. Its totient is φ = 68499264.

The previous prime is 68518477. The next prime is 68518507. The reversal of 68518481 is 18481586.

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 4774225 + 63744256 = 2185^2 + 7984^2 .

It is a cyclic number.

It is not a de Polignac number, because 68518481 - 2² = 68518477 is a prime.

It is a super-2 number, since 2×68518481² = 9389564477094722, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (68518781) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2516 + ... + 11973.

It is an arithmetic number, because the mean of its divisors is an integer number (17134425).

Almost surely, 2^68518481 is an apocalyptic number.

It is an amenable number.

68518481 is a deficient number, since it is larger than the sum of its proper divisors (19219).

68518481 is a wasteful number, since it uses less digits than its factorization.

68518481 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19218.

The product of its digits is 61440, while the sum is 41.

The square root of 68518481 is about 8277.5890813690. The cubic root of 68518481 is about 409.2002673758.

The spelling of 68518481 in words is "sixty-eight million, five hundred eighteen thousand, four hundred eighty-one".