19919216 has 20 divisors (see below), whose sum is σ = 38762400. Its totient is φ = 9916032.

The previous prime is 19919203. The next prime is 19919243. The reversal of 19919216 is 61291991.

It is a Smith number, since the sum of its digits (38) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 19919216.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1220 + ... + 6428.

It is an arithmetic number, because the mean of its divisors is an integer number (1938120).

Almost surely, 2^19919216 is an apocalyptic number.

19919216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

19919216 is a deficient number, since it is larger than the sum of its proper divisors (18843184).

19919216 is a wasteful number, since it uses less digits than its factorization.

19919216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5456 (or 5450 counting only the distinct ones).

The product of its digits is 8748, while the sum is 38.

The square root of 19919216 is about 4463.0948903199. The cubic root of 19919216 is about 271.0757992967.

The spelling of 19919216 in words is "nineteen million, nine hundred nineteen thousand, two hundred sixteen".