77381856 has 72 divisors (see below), whose sum is σ = 221752440. Its totient is φ = 25595136.

The previous prime is 77381849. The next prime is 77381873. The reversal of 77381856 is 65818377.

It is a tau number, because it is divible by the number of its divisors (72).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 39066 + ... + 40998.

It is an arithmetic number, because the mean of its divisors is an integer number (3079895).

Almost surely, 2^77381856 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 77381856, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (110876220).

77381856 is an abundant number, since it is smaller than the sum of its proper divisors (144370584).

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

77381856 is a wasteful number, since it uses less digits than its factorization.

77381856 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2088 (or 2077 counting only the distinct ones).

The product of its digits is 282240, while the sum is 45.

The square root of 77381856 is about 8796.6957432891. The cubic root of 77381856 is about 426.1341903513.

The spelling of 77381856 in words is "seventy-seven million, three hundred eighty-one thousand, eight hundred fifty-six".