38778640 has 20 divisors (see below), whose sum is σ = 90160524. Its totient is φ = 15511424.

The previous prime is 38778629. The next prime is 38778643. The reversal of 38778640 is 4687783.

38778640 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 6697744 + 32080896 = 2588^2 + 5664^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is not an unprimeable number, because it can be changed into a prime (38778643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 242287 + ... + 242446.

Almost surely, 2^38778640 is an apocalyptic number.

It is an amenable number.

38778640 is an abundant number, since it is smaller than the sum of its proper divisors (51381884).

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

38778640 is a wasteful number, since it uses less digits than its factorization.

38778640 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 484746 (or 484740 counting only the distinct ones).

The product of its (nonzero) digits is 225792, while the sum is 43.

The square root of 38778640 is about 6227.2497942511. The cubic root of 38778640 is about 338.4783209521.

The spelling of 38778640 in words is "thirty-eight million, seven hundred seventy-eight thousand, six hundred forty".