78686544 has 40 divisors (see below), whose sum is σ = 208236672. Its totient is φ = 25588480.

The previous prime is 78686537. The next prime is 78686551. The reversal of 78686544 is 44568687.

It is an interprime number because it is at equal distance from previous prime (78686537) and next prime (78686551).

It is a Smith number, since the sum of its digits (48) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (48).

It is a junction number, because it is equal to n+sod(n) for n = 78686493 and 78686502.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18024 + ... + 21959.

Almost surely, 2^78686544 is an apocalyptic number.

It is an amenable number.

78686544 is an abundant number, since it is smaller than the sum of its proper divisors (129550128).

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

78686544 is a wasteful number, since it uses less digits than its factorization.

78686544 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40035 (or 40029 counting only the distinct ones).

The product of its digits is 1290240, while the sum is 48.

The square root of 78686544 is about 8870.5436135560. The cubic root of 78686544 is about 428.5157842677.

The spelling of 78686544 in words is "seventy-eight million, six hundred eighty-six thousand, five hundred forty-four".