68868781 has 4 divisors (see below), whose sum is σ = 69042652. Its totient is φ = 68694912.

The previous prime is 68868733. The next prime is 68868791. The reversal of 68868781 is 18786886.

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 15139881 + 53728900 = 3891^2 + 7330^2 .

It is a cyclic number.

It is not a de Polignac number, because 68868781 - 2⁹ = 68868269 is a prime.

It is a super-3 number, since 3×68868781³ (a number of 24 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68868721) 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, 86340 + ... + 87133.

It is an arithmetic number, because the mean of its divisors is an integer number (17260663).

Almost surely, 2^68868781 is an apocalyptic number.

It is an amenable number.

68868781 is a deficient number, since it is larger than the sum of its proper divisors (173871).

68868781 is a wasteful number, since it uses less digits than its factorization.

68868781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 173870.

The product of its digits is 1032192, while the sum is 52.

The square root of 68868781 is about 8298.7216485432. The cubic root of 68868781 is about 409.8964263460.

The spelling of 68868781 in words is "sixty-eight million, eight hundred sixty-eight thousand, seven hundred eighty-one".