68391920 has 20 divisors (see below), whose sum is σ = 159011400. Its totient is φ = 27356736.

The previous prime is 68391893. The next prime is 68391929. The reversal of 68391920 is 2919386.

It is a tau number, because it is divible by the number of its divisors (20).

It is a plaindrome in base 13.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (68391929) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 427370 + ... + 427529.

It is an arithmetic number, because the mean of its divisors is an integer number (7950570).

Almost surely, 2^68391920 is an apocalyptic number.

It is an amenable number.

68391920 is an abundant number, since it is smaller than the sum of its proper divisors (90619480).

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

68391920 is a wasteful number, since it uses less digits than its factorization.

68391920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 854912 (or 854906 counting only the distinct ones).

The product of its (nonzero) digits is 23328, while the sum is 38.

The square root of 68391920 is about 8269.9407494855. The cubic root of 68391920 is about 408.9481664655.

The spelling of 68391920 in words is "sixty-eight million, three hundred ninety-one thousand, nine hundred twenty".