19919688 has 16 divisors (see below), whose sum is σ = 49799280. Its totient is φ = 6639888.

The previous prime is 19919687. The next prime is 19919693. The reversal of 19919688 is 88691991.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 19919688.

It is not an unprimeable number, because it can be changed into a prime (19919687) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 414970 + ... + 415017.

It is an arithmetic number, because the mean of its divisors is an integer number (3112455).

Almost surely, 2^19919688 is an apocalyptic number.

It is an amenable number.

19919688 is an abundant number, since it is smaller than the sum of its proper divisors (29879592).

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

19919688 is a wasteful number, since it uses less digits than its factorization.

19919688 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 829996 (or 829992 counting only the distinct ones).

The product of its digits is 279936, while the sum is 51.

The square root of 19919688 is about 4463.1477681116. The cubic root of 19919688 is about 271.0779403911.

The spelling of 19919688 in words is "nineteen million, nine hundred nineteen thousand, six hundred eighty-eight".