55555777778 has 6 divisors (see below), whose sum is σ = 83334166671. Its totient is φ = 27777722222.

The previous prime is 55555777727. The next prime is 55555777883. The reversal of 55555777778 is 87777755555.

It can be written as a sum of positive squares in only one way, i.e., 27777888889 + 27777888889 = 166667^2 + 166667^2 .

It is an ABA number since it can be written as A⋅B^A, here for A=2, B=166667.

It is a Duffinian number.

It is a plaindrome in base 10.

It is an unprimeable number.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 250001 + ... + 416667.

Almost surely, 2^55555777778 is an apocalyptic number.

55555777778 is a deficient number, since it is larger than the sum of its proper divisors (27778388893).

55555777778 is an frugal number, since it uses more digits than its factorization.

55555777778 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 333336 (or 166669 counting only the distinct ones).

The product of its digits is 420175000, while the sum is 68.

The spelling of 55555777778 in words is "fifty-five billion, five hundred fifty-five million, seven hundred seventy-seven thousand, seven hundred seventy-eight".