68421664 has 24 divisors (see below), whose sum is σ = 136019520. Its totient is φ = 33877056.

The previous prime is 68421649. The next prime is 68421671. The reversal of 68421664 is 46612486.

It is a Smith number, since the sum of its digits (37) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7084 + ... + 13675.

It is an arithmetic number, because the mean of its divisors is an integer number (5667480).

Almost surely, 2^68421664 is an apocalyptic number.

It is an amenable number.

68421664 is a deficient number, since it is larger than the sum of its proper divisors (67597856).

68421664 is a wasteful number, since it uses less digits than its factorization.

68421664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20872 (or 20864 counting only the distinct ones).

The product of its digits is 55296, while the sum is 37.

The square root of 68421664 is about 8271.7388740216. The cubic root of 68421664 is about 409.0074424313.

The spelling of 68421664 in words is "sixty-eight million, four hundred twenty-one thousand, six hundred sixty-four".