19685916 has 84 divisors (see below), whose sum is σ = 53189752. Its totient is φ = 6368544.

The previous prime is 19685909. The next prime is 19685917. The reversal of 19685916 is 61958691.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19685917) by changing a digit.

It is a polite number, since it can be written in 27 ways as a sum of consecutive naturals, for example, 125310 + ... + 125466.

Almost surely, 2^19685916 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 19685916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26594876).

19685916 is an abundant number, since it is smaller than the sum of its proper divisors (33503836).

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

19685916 is a wasteful number, since it uses less digits than its factorization.

19685916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 222 (or 205 counting only the distinct ones).

The product of its digits is 116640, while the sum is 45.

The square root of 19685916 is about 4436.8813371556. The cubic root of 19685916 is about 270.0133326750.

The spelling of 19685916 in words is "nineteen million, six hundred eighty-five thousand, nine hundred sixteen".