64666655 has 16 divisors (see below), whose sum is σ = 79349760. Its totient is φ = 50576928.

The previous prime is 64666643. The next prime is 64666661. The reversal of 64666655 is 55666646.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-64666655 is a prime.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 65294 + ... + 66276.

It is an arithmetic number, because the mean of its divisors is an integer number (4959360).

Almost surely, 2^64666655 is an apocalyptic number.

64666655 is a deficient number, since it is larger than the sum of its proper divisors (14683105).

64666655 is a wasteful number, since it uses less digits than its factorization.

64666655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1270.

The product of its digits is 777600, while the sum is 44.

The square root of 64666655 is about 8041.5579958115. The cubic root of 64666655 is about 401.3840699356.

Subtracting from 64666655 its reverse (55666646), we obtain a palindrome (9000009).

The spelling of 64666655 in words is "sixty-four million, six hundred sixty-six thousand, six hundred fifty-five".