68028640 has 48 divisors (see below), whose sum is σ = 161623728. Its totient is φ = 27058176.

The previous prime is 68028629. The next prime is 68028643. The reversal of 68028640 is 4682086.

It is a junction number, because it is equal to n+sod(n) for n = 68028596 and 68028605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68028643) 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, 29779 + ... + 31981.

It is an arithmetic number, because the mean of its divisors is an integer number (3367161).

Almost surely, 2^68028640 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 68028640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (80811864).

68028640 is an abundant number, since it is smaller than the sum of its proper divisors (93595088).

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

68028640 is a wasteful number, since it uses less digits than its factorization.

68028640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2411 (or 2403 counting only the distinct ones).

The product of its (nonzero) digits is 18432, while the sum is 34.

The square root of 68028640 is about 8247.9476235000. The cubic root of 68028640 is about 408.2228053850. Note that the first 3 decimals are identical.

The spelling of 68028640 in words is "sixty-eight million, twenty-eight thousand, six hundred forty".