19897216 has 32 divisors (see below), whose sum is σ = 39841200. Its totient is φ = 9897984.

The previous prime is 19897193. The next prime is 19897223. The reversal of 19897216 is 61279891.

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 polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 45736 + ... + 46168.

Almost surely, 2^19897216 is an apocalyptic number.

19897216 is a gapful number since it is divisible by the number (16) formed by its first and last digit.

It is an amenable number.

19897216 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

19897216 is an equidigital number, since it uses as much as digits as its factorization.

19897216 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 806 (or 794 counting only the distinct ones).

The product of its digits is 54432, while the sum is 43.

The square root of 19897216 is about 4460.6295519803. The cubic root of 19897216 is about 270.9759649712.

The spelling of 19897216 in words is "nineteen million, eight hundred ninety-seven thousand, two hundred sixteen".