77728705558541 has 4 divisors (see below), whose sum is σ = 77824785541500. Its totient is φ = 77632625575584.

The previous prime is 77728705558523. The next prime is 77728705558561. The reversal of 77728705558541 is 14585550782777.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 62335998949225 + 15392706609316 = 7895315^2 + 3923354^2 .

It is a cyclic number.

It is not a de Polignac number, because 77728705558541 - 2⁶ = 77728705558477 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77728705558561) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 48039990266 + ... + 48039991883.

It is an arithmetic number, because the mean of its divisors is an integer number (19456196385375).

Almost surely, 2^{77728705558541} is an apocalyptic number.

It is an amenable number.

77728705558541 is a deficient number, since it is larger than the sum of its proper divisors (96079982959).

77728705558541 is an equidigital number, since it uses as much as digits as its factorization.

77728705558541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96079982958.

The product of its (nonzero) digits is 768320000, while the sum is 71.

The spelling of 77728705558541 in words is "seventy-seven trillion, seven hundred twenty-eight billion, seven hundred five million, five hundred fifty-eight thousand, five hundred forty-one".