19971968 has 32 divisors (see below), whose sum is σ = 39992160. Its totient is φ = 9934848.

The previous prime is 19971953. The next prime is 19971979. The reversal of 19971968 is 86917991.

It is a tau number, because it is divible by the number of its divisors (32).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 42905 + ... + 43367.

It is an arithmetic number, because the mean of its divisors is an integer number (1249755).

Almost surely, 2^19971968 is an apocalyptic number.

It is an amenable number.

19971968 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

19971968 is an equidigital number, since it uses as much as digits as its factorization.

19971968 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 814 (or 802 counting only the distinct ones).

The product of its digits is 244944, while the sum is 50.

The square root of 19971968 is about 4469.0007831729. Note that the first 3 decimals coincide. The cubic root of 19971968 is about 271.3148847731.

The spelling of 19971968 in words is "nineteen million, nine hundred seventy-one thousand, nine hundred sixty-eight".