77840256 has 128 divisors (see below), whose sum is σ = 230307840. Its totient is φ = 23132160.

The previous prime is 77840239. The next prime is 77840299. The reversal of 77840256 is 65204877.

It is a tau number, because it is divible by the number of its divisors (128).

It is a Harshad number since it is a multiple of its sum of digits (39).

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 15 ways as a sum of consecutive naturals, for example, 154501 + ... + 155003.

It is an arithmetic number, because the mean of its divisors is an integer number (1799280).

Almost surely, 2^77840256 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 77840256, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (115153920).

77840256 is an abundant number, since it is smaller than the sum of its proper divisors (152467584).

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

77840256 is a wasteful number, since it uses less digits than its factorization.

77840256 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 564 (or 552 counting only the distinct ones).

The product of its (nonzero) digits is 94080, while the sum is 39.

The square root of 77840256 is about 8822.7125080669. The cubic root of 77840256 is about 426.9739886566.

The spelling of 77840256 in words is "seventy-seven million, eight hundred forty thousand, two hundred fifty-six".