78646 has 4 divisors (see below), whose sum is σ = 117972. Its totient is φ = 39322.

The previous prime is 78643. The next prime is 78649. The reversal of 78646 is 64687.

78646 is nontrivially palindromic in base 15.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 64687 = 7 ⋅9241.

It is an interprime number because it is at equal distance from previous prime (78643) and next prime (78649).

It is a plaindrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78643) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 19660 + ... + 19663.

It is an arithmetic number, because the mean of its divisors is an integer number (29493).

2⁷⁸⁶⁴⁶ is an apocalyptic number.

78646 is a deficient number, since it is larger than the sum of its proper divisors (39326).

78646 is a wasteful number, since it uses less digits than its factorization.

78646 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 39325.

The product of its digits is 8064, while the sum is 31.

The square root of 78646 is about 280.4389416611. The cubic root of 78646 is about 42.8442172661.

The spelling of 78646 in words is "seventy-eight thousand, six hundred forty-six".