77755428 has 36 divisors (see below), whose sum is σ = 197650908. Its totient is φ = 25773120.

The previous prime is 77755427. The next prime is 77755441. The reversal of 77755428 is 82455777.

77755428 is a `hidden beast` number, since 7 + 77 + 554 + 28 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 27373824 + 50381604 = 5232^2 + 7098^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is not an unprimeable number, because it can be changed into a prime (77755427) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 550 + ... + 12482.

It is an arithmetic number, because the mean of its divisors is an integer number (5490303).

Almost surely, 2^77755428 is an apocalyptic number.

It is an amenable number.

77755428 is an abundant number, since it is smaller than the sum of its proper divisors (119895480).

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

77755428 is a wasteful number, since it uses less digits than its factorization.

77755428 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12124 (or 12119 counting only the distinct ones).

The product of its digits is 548800, while the sum is 45.

The square root of 77755428 is about 8817.9038325443. The cubic root of 77755428 is about 426.8188310887.

It can be divided in two parts, 7775 and 5428, that added together give a triangular number (13203 = T₁₆₂).

The spelling of 77755428 in words is "seventy-seven million, seven hundred fifty-five thousand, four hundred twenty-eight".