78617647 has 4 divisors (see below), whose sum is σ = 78662416. Its totient is φ = 78572880.

The previous prime is 78617641. The next prime is 78617653. The reversal of 78617647 is 74671687.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (78617641) and next prime (78617653).

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78617647 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 78617597 and 78617606.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78617641) 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, 19638 + ... + 23299.

It is an arithmetic number, because the mean of its divisors is an integer number (19665604).

Almost surely, 2^78617647 is an apocalyptic number.

78617647 is a deficient number, since it is larger than the sum of its proper divisors (44769).

78617647 is a wasteful number, since it uses less digits than its factorization.

78617647 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44768.

The product of its digits is 395136, while the sum is 46.

The square root of 78617647 is about 8866.6592919769. The cubic root of 78617647 is about 428.3906799764.

The spelling of 78617647 in words is "seventy-eight million, six hundred seventeen thousand, six hundred forty-seven".