19721982 has 32 divisors (see below), whose sum is σ = 45229824. Its totient is φ = 5616000.

The previous prime is 19721963. The next prime is 19722013. The reversal of 19721982 is 28912791.

It is a self number, because there is not a number n which added to its sum of digits gives 19721982.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16257 + ... + 17427.

It is an arithmetic number, because the mean of its divisors is an integer number (1413432).

Almost surely, 2^19721982 is an apocalyptic number.

19721982 is an abundant number, since it is smaller than the sum of its proper divisors (25507842).

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

19721982 is a wasteful number, since it uses less digits than its factorization.

19721982 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1584.

The product of its digits is 18144, while the sum is 39.

The square root of 19721982 is about 4440.9438186043. The cubic root of 19721982 is about 270.1781266291.

The spelling of 19721982 in words is "nineteen million, seven hundred twenty-one thousand, nine hundred eighty-two".