19778648 has 16 divisors (see below), whose sum is σ = 37503000. Its totient is φ = 9777856.

The previous prime is 19778641. The next prime is 19778657. The reversal of 19778648 is 84687791.

It is a junction number, because it is equal to n+sod(n) for n = 19778596 and 19778605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19778641) 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, 13178 + ... + 14601.

Almost surely, 2^19778648 is an apocalyptic number.

It is an amenable number.

19778648 is a deficient number, since it is larger than the sum of its proper divisors (17724352).

19778648 is a wasteful number, since it uses less digits than its factorization.

19778648 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27874 (or 27870 counting only the distinct ones).

The product of its digits is 677376, while the sum is 50.

The square root of 19778648 is about 4447.3191925024. The cubic root of 19778648 is about 270.4366414522.

The spelling of 19778648 in words is "nineteen million, seven hundred seventy-eight thousand, six hundred forty-eight".