78821856 has 48 divisors (see below), whose sum is σ = 229899600. Its totient is φ = 26273664.

The previous prime is 78821839. The next prime is 78821879. The reversal of 78821856 is 65812887.

It is a tau number, because it is divible by the number of its divisors (48).

It is a super-3 number, since 3×78821856³ (a number of 25 digits) contains 333 as substring.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 44751 + ... + 46478.

It is an arithmetic number, because the mean of its divisors is an integer number (4789575).

Almost surely, 2^78821856 is an apocalyptic number.

It is an amenable number.

78821856 is an abundant number, since it is smaller than the sum of its proper divisors (151077744).

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

78821856 is a wasteful number, since it uses less digits than its factorization.

78821856 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 91248 (or 91234 counting only the distinct ones).

The product of its digits is 215040, while the sum is 45.

The square root of 78821856 is about 8878.1673784627. The cubic root of 78821856 is about 428.7612736059.

The spelling of 78821856 in words is "seventy-eight million, eight hundred twenty-one thousand, eight hundred fifty-six".