2551557778 has 64 divisors (see below), whose sum is σ = 5138380800. Its totient is φ = 919722240.

The previous prime is 2551557737. The next prime is 2551557781. The reversal of 2551557778 is 8777551552.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 146203 + ... + 162721.

It is an arithmetic number, because the mean of its divisors is an integer number (80287200).

Almost surely, 2^2551557778 is an apocalyptic number.

2551557778 is an abundant number, since it is smaller than the sum of its proper divisors (2586823022).

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

2551557778 is a wasteful number, since it uses less digits than its factorization.

2551557778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16615.

The product of its digits is 3430000, while the sum is 52.

The square root of 2551557778 is about 50512.9466374711. The cubic root of 2551557778 is about 1366.4753516717.

The spelling of 2551557778 in words is "two billion, five hundred fifty-one million, five hundred fifty-seven thousand, seven hundred seventy-eight".