66551233215566 has 16 divisors (see below), whose sum is σ = 110687296974768. Its totient is φ = 29754649723200.

The previous prime is 66551233215559. The next prime is 66551233215569.

66551233215566 is nontrivially palindromic in base 10.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66551233215569) 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, 24795540095 + ... + 24795542778.

It is an arithmetic number, because the mean of its divisors is an integer number (6917956060923).

Almost surely, 2^{66551233215566} is an apocalyptic number.

66551233215566 is a deficient number, since it is larger than the sum of its proper divisors (44136063759202).

66551233215566 is a wasteful number, since it uses less digits than its factorization.

66551233215566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49591082947.

The product of its digits is 29160000, while the sum is 56.

The spelling of 66551233215566 in words is "sixty-six trillion, five hundred fifty-one billion, two hundred thirty-three million, two hundred fifteen thousand, five hundred sixty-six".