155555557778 has 8 divisors (see below), whose sum is σ = 234542318268. Its totient is φ = 77374785024.

The previous prime is 155555557763. The next prime is 155555557811. The reversal of 155555557778 is 877755555551.

155555557778 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 151248654649 + 4306903129 = 388907^2 + 65627^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a plaindrome in base 10.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 201496451 + ... + 201497222.

Almost surely, 2^155555557778 is an apocalyptic number.

155555557778 is a deficient number, since it is larger than the sum of its proper divisors (78986760490).

155555557778 is a wasteful number, since it uses less digits than its factorization.

155555557778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 402993868.

The product of its digits is 214375000, while the sum is 65.

The spelling of 155555557778 in words is "one hundred fifty-five billion, five hundred fifty-five million, five hundred fifty-seven thousand, seven hundred seventy-eight".