68304640 has 144 divisors (see below), whose sum is σ = 179692128. Its totient is φ = 24772608.

The previous prime is 68304631. The next prime is 68304667. The reversal of 68304640 is 4640386.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 935644 + ... + 935716.

It is an arithmetic number, because the mean of its divisors is an integer number (1247862).

Almost surely, 2^68304640 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 68304640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (89846064).

68304640 is an abundant number, since it is smaller than the sum of its proper divisors (111387488).

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

68304640 is a wasteful number, since it uses less digits than its factorization.

68304640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154 (or 140 counting only the distinct ones).

The product of its (nonzero) digits is 13824, while the sum is 31.

The square root of 68304640 is about 8264.6621225553. The cubic root of 68304640 is about 408.7741293851.

The spelling of 68304640 in words is "sixty-eight million, three hundred four thousand, six hundred forty".