77856880 has 80 divisors (see below), whose sum is σ = 192532320. Its totient is φ = 29223936.

The previous prime is 77856871. The next prime is 77856893. The reversal of 77856880 is 8865877.

It is a tau number, because it is divible by the number of its divisors (80).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85387 + ... + 86293.

It is an arithmetic number, because the mean of its divisors is an integer number (2406654).

Almost surely, 2^77856880 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 77856880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (96266160).

77856880 is an abundant number, since it is smaller than the sum of its proper divisors (114675440).

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

77856880 is a wasteful number, since it uses less digits than its factorization.

77856880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 986 (or 980 counting only the distinct ones).

The product of its (nonzero) digits is 752640, while the sum is 49.

The square root of 77856880 is about 8823.6545716613. The cubic root of 77856880 is about 427.0043821433.

The spelling of 77856880 in words is "seventy-seven million, eight hundred fifty-six thousand, eight hundred eighty".