77737680 has 120 divisors (see below), whose sum is σ = 263900520. Its totient is φ = 20505600.

The previous prime is 77737663. The next prime is 77737711. The reversal of 77737680 is 8673777.

It can be written as a sum of positive squares in 4 ways, for example, as 24681024 + 53056656 = 4968^2 + 7284^2 .

It is a tau number, because it is divible by the number of its divisors (120).

It is a Harshad number since it is a multiple of its sum of digits (45).

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 23 ways as a sum of consecutive naturals, for example, 72186 + ... + 73254.

It is an arithmetic number, because the mean of its divisors is an integer number (2199171).

Almost surely, 2^77737680 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 77737680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (131950260).

77737680 is an abundant number, since it is smaller than the sum of its proper divisors (186162840).

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

77737680 is a wasteful number, since it uses less digits than its factorization.

77737680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1189 (or 1180 counting only the distinct ones).

The product of its (nonzero) digits is 345744, while the sum is 45.

The square root of 77737680 is about 8816.8974134896. The cubic root of 77737680 is about 426.7863542262.

The spelling of 77737680 in words is "seventy-seven million, seven hundred thirty-seven thousand, six hundred eighty".