77727744 has 72 divisors (see below), whose sum is σ = 224545230. Its totient is φ = 25903104.

The previous prime is 77727731. The next prime is 77727761. The reversal of 77727744 is 44772777.

It can be written as a sum of positive squares in only one way, i.e., 51840000 + 25887744 = 7200^2 + 5088^2 .

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

It is a self number, because there is not a number n which added to its sum of digits gives 77727744.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 16324 + ... + 20540.

Almost surely, 2^77727744 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 77727744, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (112272615).

77727744 is an abundant number, since it is smaller than the sum of its proper divisors (146817486).

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

77727744 is a wasteful number, since it uses less digits than its factorization.

77727744 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4245 (or 4222 counting only the distinct ones).

The product of its digits is 537824, while the sum is 45.

The square root of 77727744 is about 8816.3339319697. Note that the first 3 decimals coincide. The cubic root of 77727744 is about 426.7681702949.

It can be divided in two parts, 77 and 727744, that added together give a triangular number (727821 = T₁₂₀₆).

The spelling of 77727744 in words is "seventy-seven million, seven hundred twenty-seven thousand, seven hundred forty-four".