66009655 has 16 divisors (see below), whose sum is σ = 85510080. Its totient is φ = 48767488.

The previous prime is 66009607. The next prime is 66009683. The reversal of 66009655 is 55690066.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 66009655 - 2⁷ = 66009527 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6562 + ... + 13231.

It is an arithmetic number, because the mean of its divisors is an integer number (5344380).

Almost surely, 2^66009655 is an apocalyptic number.

66009655 is a deficient number, since it is larger than the sum of its proper divisors (19500425).

66009655 is a wasteful number, since it uses less digits than its factorization.

66009655 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19850.

The product of its (nonzero) digits is 48600, while the sum is 37.

The square root of 66009655 is about 8124.6326070783. The cubic root of 66009655 is about 404.1437072490.

The spelling of 66009655 in words is "sixty-six million, nine thousand, six hundred fifty-five".