2581457778 has 12 divisors (see below), whose sum is σ = 5593158558. Its totient is φ = 860485920.

The previous prime is 2581457759. The next prime is 2581457779. The reversal of 2581457778 is 8777541852.

2581457778 is a `hidden beast` number, since 2 + 58 + 14 + 577 + 7 + 8 = 666.

It can be written as a sum of positive squares in only one way, i.e., 2576273049 + 5184729 = 50757^2 + 2277^2 .

It is not an unprimeable number, because it can be changed into a prime (2581457779) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 71707143 + ... + 71707178.

Almost surely, 2^2581457778 is an apocalyptic number.

2581457778 is an abundant number, since it is smaller than the sum of its proper divisors (3011700780).

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

2581457778 is a wasteful number, since it uses less digits than its factorization.

2581457778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 143414329 (or 143414326 counting only the distinct ones).

The product of its digits is 4390400, while the sum is 54.

The square root of 2581457778 is about 50808.0483585032. The cubic root of 2581457778 is about 1371.7922408227.

The spelling of 2581457778 in words is "two billion, five hundred eighty-one million, four hundred fifty-seven thousand, seven hundred seventy-eight".