68666688 has 84 divisors (see below), whose sum is σ = 199011540. Its totient is φ = 22634496.

The previous prime is 68666687. The next prime is 68666699. The reversal of 68666688 is 88666686.

It can be written as a sum of positive squares in 2 ways, for example, as 54287424 + 14379264 = 7368^2 + 3792^2 .

It is a super-2 number, since 2×68666688² = 9430228081778688, which contains 22 as substring.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68666681) 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, 55258 + ... + 56486.

It is an arithmetic number, because the mean of its divisors is an integer number (2369185).

Almost surely, 2^68666688 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 68666688, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99505770).

68666688 is an abundant number, since it is smaller than the sum of its proper divisors (130344852).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

68666688 is a wasteful number, since it uses less digits than its factorization.

68666688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1344 (or 1331 counting only the distinct ones).

The product of its digits is 3981312, while the sum is 54.

The square root of 68666688 is about 8286.5365503327. The cubic root of 68666688 is about 409.4950913374.

The spelling of 68666688 in words is "sixty-eight million, six hundred sixty-six thousand, six hundred eighty-eight".