2578778555 has 16 divisors (see below), whose sum is σ = 3225391104. Its totient is φ = 1977078240.

The previous prime is 2578778551. The next prime is 2578778557. The reversal of 2578778555 is 5558778752.

It is a happy number.

It is not a de Polignac number, because 2578778555 - 2² = 2578778551 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2578778494 and 2578778503.

It is not an unprimeable number, because it can be changed into a prime (2578778551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 64799 + ... + 96728.

It is an arithmetic number, because the mean of its divisors is an integer number (201586944).

Almost surely, 2^2578778555 is an apocalyptic number.

2578778555 is a deficient number, since it is larger than the sum of its proper divisors (646612549).

2578778555 is a wasteful number, since it uses less digits than its factorization.

2578778555 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 161666.

The product of its digits is 27440000, while the sum is 59.

The square root of 2578778555 is about 50781.6753859106. The cubic root of 2578778555 is about 1371.3174949126.

The spelling of 2578778555 in words is "two billion, five hundred seventy-eight million, seven hundred seventy-eight thousand, five hundred fifty-five".