66066566 has 4 divisors (see below), whose sum is σ = 99099852. Its totient is φ = 33033282.

The previous prime is 66066563. The next prime is 66066587. The reversal of 66066566 is 66566066.

It is a semiprime because it is the product of two primes.

It is a super-2 number, since 2×66066566² = 8729582286064712, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66066563) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16516640 + ... + 16516643.

It is an arithmetic number, because the mean of its divisors is an integer number (24774963).

Almost surely, 2^66066566 is an apocalyptic number.

66066566 is a deficient number, since it is larger than the sum of its proper divisors (33033286).

66066566 is a wasteful number, since it uses less digits than its factorization.

66066566 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33033285.

The product of its (nonzero) digits is 233280, while the sum is 41.

The square root of 66066566 is about 8128.1342262539. The cubic root of 66066566 is about 404.2598196355.

Subtracting 66066566 from its reverse (66566066), we obtain a triangular number (499500 = T₉₉₉).

The spelling of 66066566 in words is "sixty-six million, sixty-six thousand, five hundred sixty-six".