68816640 has 72 divisors (see below), whose sum is σ = 219795408. Its totient is φ = 18350080.

The previous prime is 68816609. The next prime is 68816647. The reversal of 68816640 is 4661886.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68816647) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5121 + ... + 12800.

It is an arithmetic number, because the mean of its divisors is an integer number (3052714).

Almost surely, 2^68816640 is an apocalyptic number.

68816640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

68816640 is an abundant number, since it is smaller than the sum of its proper divisors (150978768).

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

68816640 is a wasteful number, since it uses less digits than its factorization.

68816640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 17945 (or 17931 counting only the distinct ones).

The product of its (nonzero) digits is 55296, while the sum is 39.

The square root of 68816640 is about 8295.5795457581. The cubic root of 68816640 is about 409.7929551492.

The spelling of 68816640 in words is "sixty-eight million, eight hundred sixteen thousand, six hundred forty".