19981964 has 12 divisors (see below), whose sum is σ = 35044800. Its totient is φ = 9969168.

The previous prime is 19981937. The next prime is 19981967. The reversal of 19981964 is 46918991.

It is not an unprimeable number, because it can be changed into a prime (19981967) by changing a digit.

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, 3299 + ... + 7130.

It is an arithmetic number, because the mean of its divisors is an integer number (2920400).

Almost surely, 2^19981964 is an apocalyptic number.

It is an amenable number.

19981964 is a deficient number, since it is larger than the sum of its proper divisors (15062836).

19981964 is a wasteful number, since it uses less digits than its factorization.

19981964 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10912 (or 10910 counting only the distinct ones).

The product of its digits is 139968, while the sum is 47.

The square root of 19981964 is about 4470.1190140756. The cubic root of 19981964 is about 271.3601417261.

The spelling of 19981964 in words is "nineteen million, nine hundred eighty-one thousand, nine hundred sixty-four".