19778768 has 10 divisors (see below), whose sum is σ = 38321394. Its totient is φ = 9889376.

The previous prime is 19778767. The next prime is 19778777. The reversal of 19778768 is 86787791.

It can be written as a sum of positive squares in only one way, i.e., 15147664 + 4631104 = 3892^2 + 2152^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19778761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 618071 + ... + 618102.

Almost surely, 2^19778768 is an apocalyptic number.

It is an amenable number.

19778768 is a deficient number, since it is larger than the sum of its proper divisors (18542626).

19778768 is a wasteful number, since it uses less digits than its factorization.

19778768 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1236181 (or 1236175 counting only the distinct ones).

The product of its digits is 1185408, while the sum is 53.

The square root of 19778768 is about 4447.3326837555. The cubic root of 19778768 is about 270.4371883775.

The spelling of 19778768 in words is "nineteen million, seven hundred seventy-eight thousand, seven hundred sixty-eight".