19938644 has 24 divisors (see below), whose sum is σ = 38329536. Its totient is φ = 9000000.

The previous prime is 19938613. The next prime is 19938647. The reversal of 19938644 is 44683991.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a junction number, because it is equal to n+sod(n) for n = 19938595 and 19938604.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19938647) 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 7 ways as a sum of consecutive naturals, for example, 5144 + ... + 8144.

It is an arithmetic number, because the mean of its divisors is an integer number (1597064).

Almost surely, 2^19938644 is an apocalyptic number.

It is an amenable number.

19938644 is a deficient number, since it is larger than the sum of its proper divisors (18390892).

19938644 is a wasteful number, since it uses less digits than its factorization.

19938644 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3167 (or 3165 counting only the distinct ones).

The product of its digits is 186624, while the sum is 44.

The square root of 19938644 is about 4465.2708764419. The cubic root of 19938644 is about 271.1639009797.

The spelling of 19938644 in words is "nineteen million, nine hundred thirty-eight thousand, six hundred forty-four".