19691916 has 48 divisors (see below), whose sum is σ = 49279104. Its totient is φ = 6098176.

The previous prime is 19691879. The next prime is 19691929. The reversal of 19691916 is 61919691.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 16351 + ... + 17513.

It is an arithmetic number, because the mean of its divisors is an integer number (1026648).

Almost surely, 2^19691916 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 19691916, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24639552).

19691916 is an abundant number, since it is smaller than the sum of its proper divisors (29587188).

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

19691916 is a wasteful number, since it uses less digits than its factorization.

19691916 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1270 (or 1268 counting only the distinct ones).

The product of its digits is 26244, while the sum is 42.

The square root of 19691916 is about 4437.5574362480. The cubic root of 19691916 is about 270.0407620214.

The spelling of 19691916 in words is "nineteen million, six hundred ninety-one thousand, nine hundred sixteen".