2506656666 has 8 divisors (see below), whose sum is σ = 5013313344. Its totient is φ = 835552220.

The previous prime is 2506656653. The next prime is 2506656667. The reversal of 2506656666 is 6666566052.

It is a sphenic number, since it is the product of 3 distinct primes.

2506656666 is an admirable number.

It is not an unprimeable number, because it can be changed into a prime (2506656667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 208888050 + ... + 208888061.

It is an arithmetic number, because the mean of its divisors is an integer number (626664168).

Almost surely, 2^2506656666 is an apocalyptic number.

2506656666 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

2506656666 is a wasteful number, since it uses less digits than its factorization.

2506656666 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 417776116.

The product of its (nonzero) digits is 2332800, while the sum is 48.

The square root of 2506656666 is about 50066.5224076927. The cubic root of 2506656666 is about 1358.4123388258.

The spelling of 2506656666 in words is "two billion, five hundred six million, six hundred fifty-six thousand, six hundred sixty-six".