78447656 has 64 divisors (see below), whose sum is σ = 187401600. Its totient is φ = 29970432.

The previous prime is 78447623. The next prime is 78447667. The reversal of 78447656 is 65674487.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 78447656.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 15920 + ... + 20256.

It is an arithmetic number, because the mean of its divisors is an integer number (2928150).

Almost surely, 2^78447656 is an apocalyptic number.

78447656 is a gapful number since it is divisible by the number (76) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 78447656, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (93700800).

78447656 is an abundant number, since it is smaller than the sum of its proper divisors (108953944).

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

78447656 is a wasteful number, since it uses less digits than its factorization.

78447656 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4386 (or 4382 counting only the distinct ones).

The product of its digits is 1128960, while the sum is 47.

The square root of 78447656 is about 8857.0681379337. The cubic root of 78447656 is about 428.0816945986.

The spelling of 78447656 in words is "seventy-eight million, four hundred forty-seven thousand, six hundred fifty-six".