2557991766 has 32 divisors (see below), whose sum is σ = 5582866176. Its totient is φ = 774900000.

The previous prime is 2557991749. The next prime is 2557991771. The reversal of 2557991766 is 6671997552.

It is a Curzon number.

It is a congruent number.

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 15 ways as a sum of consecutive naturals, for example, 402816 + ... + 409116.

It is an arithmetic number, because the mean of its divisors is an integer number (174464568).

Almost surely, 2^2557991766 is an apocalyptic number.

2557991766 is an abundant number, since it is smaller than the sum of its proper divisors (3024874410).

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

2557991766 is a wasteful number, since it uses less digits than its factorization.

2557991766 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12468.

The product of its digits is 7144200, while the sum is 57.

The square root of 2557991766 is about 50576.5930643811. The cubic root of 2557991766 is about 1367.6229521135.

The spelling of 2557991766 in words is "two billion, five hundred fifty-seven million, nine hundred ninety-one thousand, seven hundred sixty-six".