66555255255566 has 256 divisors, whose sum is σ = 132569472172032. Its totient is φ = 24294375705600.

The previous prime is 66555255255563. The next prime is 66555255255569.

66555255255566 is nontrivially palindromic in base 10.

It is an interprime number because it is at equal distance from previous prime (66555255255563) and next prime (66555255255569).

It is a junction number, because it is equal to n+sod(n) for n = 66555255255496 and 66555255255505.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66555255255563) by changing a digit.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 37966488146 + ... + 37966489898.

It is an arithmetic number, because the mean of its divisors is an integer number (517849500672).

Almost surely, 2^{66555255255566} is an apocalyptic number.

66555255255566 is a deficient number, since it is larger than the sum of its proper divisors (66014216916466).

66555255255566 is a wasteful number, since it uses less digits than its factorization.

66555255255566 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2767.

The product of its digits is 2025000000, while the sum is 68.

The spelling of 66555255255566 in words is "sixty-six trillion, five hundred fifty-five billion, two hundred fifty-five million, two hundred fifty-five thousand, five hundred sixty-six".