68432640 has 144 divisors (see below), whose sum is σ = 222518016. Its totient is φ = 17920000.

The previous prime is 68432629. The next prime is 68432641. The reversal of 68432640 is 4623486.

It is not an unprimeable number, because it can be changed into a prime (68432641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 272515 + ... + 272765.

It is an arithmetic number, because the mean of its divisors is an integer number (1545264).

Almost surely, 2^68432640 is an apocalyptic number.

68432640 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 68432640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (111259008).

68432640 is an abundant number, since it is smaller than the sum of its proper divisors (154085376).

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

68432640 is a wasteful number, since it uses less digits than its factorization.

68432640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 346 (or 332 counting only the distinct ones).

The product of its (nonzero) digits is 27648, while the sum is 33.

The square root of 68432640 is about 8272.4023112999. The cubic root of 68432640 is about 409.0293118480.

The spelling of 68432640 in words is "sixty-eight million, four hundred thirty-two thousand, six hundred forty".