2566665716 has 6 divisors (see below), whose sum is σ = 4491665010. Its totient is φ = 1283332856.

The previous prime is 2566665701. The next prime is 2566665733. The reversal of 2566665716 is 6175666652.

It can be written as a sum of positive squares in only one way, i.e., 2523052900 + 43612816 = 50230^2 + 6604^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 320833211 + ... + 320833218.

It is an arithmetic number, because the mean of its divisors is an integer number (748610835).

Almost surely, 2^2566665716 is an apocalyptic number.

It is an amenable number.

2566665716 is a deficient number, since it is larger than the sum of its proper divisors (1924999294).

2566665716 is a wasteful number, since it uses less digits than its factorization.

2566665716 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 641666433 (or 641666431 counting only the distinct ones).

The product of its digits is 2721600, while the sum is 50.

The square root of 2566665716 is about 50662.2711295102. The cubic root of 2566665716 is about 1369.1670422831.

The spelling of 2566665716 in words is "two billion, five hundred sixty-six million, six hundred sixty-five thousand, seven hundred sixteen".