77545680 has 80 divisors (see below), whose sum is σ = 242942784. Its totient is φ = 20459520.

The previous prime is 77545661. The next prime is 77545691. The reversal of 77545680 is 8654577.

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

It is a Smith number, since the sum of its digits (42) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 21615 + ... + 24945.

Almost surely, 2^77545680 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 77545680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (121471392).

77545680 is an abundant number, since it is smaller than the sum of its proper divisors (165397104).

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

77545680 is a wasteful number, since it uses less digits than its factorization.

77545680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3444 (or 3438 counting only the distinct ones).

The product of its (nonzero) digits is 235200, while the sum is 42.

The square root of 77545680 is about 8806.0024982963. The cubic root of 77545680 is about 426.4346992121.

The spelling of 77545680 in words is "seventy-seven million, five hundred forty-five thousand, six hundred eighty".