78640047 has 6 divisors (see below), whose sum is σ = 113591192. Its totient is φ = 52426692.

The previous prime is 78640039. The next prime is 78640049. The reversal of 78640047 is 74004687.

It is a happy number.

78640047 is a `hidden beast` number, since 7 + 8 + 640 + 0 + 4 + 7 = 666.

It is not a de Polignac number, because 78640047 - 2³ = 78640039 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78639993 and 78640020.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78640049) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 4368883 + ... + 4368900.

Almost surely, 2^78640047 is an apocalyptic number.

78640047 is a deficient number, since it is larger than the sum of its proper divisors (34951145).

78640047 is a wasteful number, since it uses less digits than its factorization.

78640047 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8737789 (or 8737786 counting only the distinct ones).

The product of its (nonzero) digits is 37632, while the sum is 36.

The square root of 78640047 is about 8867.9223609592. The cubic root of 78640047 is about 428.4313622759.

The spelling of 78640047 in words is "seventy-eight million, six hundred forty thousand, forty-seven".