2545564666 has 16 divisors (see below), whose sum is σ = 4119240744.
Its totient is φ = 1175309824.
The previous prime is 2545564631. The next prime is 2545564667. The reversal of 2545564666 is 6664655452.
It can be written as a sum of positive squares in 4 ways, for example, as 2543084041 + 2480625 = 50429^2 + 1575^2
It is not an unprimeable number, because it can be changed into a prime (2545564667) by changing a digit.
It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 704515 + ... + 708118.
Almost surely, 22545564666 is an apocalyptic number.
2545564666 is a deficient number, since it is larger than the sum of its proper divisors (1573676078).
2545564666 is a wasteful number, since it uses less digits than its factorization.
2545564666 is an odious number, because the sum of its binary digits is odd.
The sum of its prime factors is 1412705.
The product of its digits is 5184000, while the sum is 49.
The square root of 2545564666 is about 50453.5892281213.
The cubic root of 2545564666 is about 1365.4046515060.
The spelling of 2545564666 in words is "two billion, five hundred forty-five million, five hundred sixty-four thousand, six hundred sixty-six".