68085640 has 64 divisors (see below), whose sum is σ = 177528960. Its totient is φ = 23016960.

The previous prime is 68085631. The next prime is 68085643. The reversal of 68085640 is 4658086.

It is a self number, because there is not a number n which added to its sum of digits gives 68085640.

It is not an unprimeable number, because it can be changed into a prime (68085643) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 18775 + ... + 22105.

It is an arithmetic number, because the mean of its divisors is an integer number (2773890).

Almost surely, 2^68085640 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 68085640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (88764480).

68085640 is an abundant number, since it is smaller than the sum of its proper divisors (109443320).

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

68085640 is a wasteful number, since it uses less digits than its factorization.

68085640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3422 (or 3418 counting only the distinct ones).

The product of its (nonzero) digits is 46080, while the sum is 37.

The square root of 68085640 is about 8251.4023050631. The cubic root of 68085640 is about 408.3367877907.

It can be divided in two parts, 680 and 85640, that added together give a triangular number (86320 = T₄₁₅).

The spelling of 68085640 in words is "sixty-eight million, eighty-five thousand, six hundred forty".