66308661 has 12 divisors (see below), whose sum is σ = 95902092. Its totient is φ = 44149056.

The previous prime is 66308639. The next prime is 66308677. The reversal of 66308661 is 16680366.

It can be written as a sum of positive squares in 2 ways, for example, as 55219761 + 11088900 = 7431^2 + 3330^2 .

It is not a de Polignac number, because 66308661 - 2¹⁴ = 66292277 is a prime.

It is a super-2 number, since 2×66308661² = 8793677047225842, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66308261) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 3415 + ... + 12011.

It is an arithmetic number, because the mean of its divisors is an integer number (7991841).

Almost surely, 2^66308661 is an apocalyptic number.

It is an amenable number.

66308661 is a deficient number, since it is larger than the sum of its proper divisors (29593431).

66308661 is a wasteful number, since it uses less digits than its factorization.

66308661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9460 (or 9457 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 36.

The square root of 66308661 is about 8143.0130173051. The cubic root of 66308661 is about 404.7530089814.

The spelling of 66308661 in words is "sixty-six million, three hundred eight thousand, six hundred sixty-one".