66118649 has 4 divisors (see below), whose sum is σ = 67656336. Its totient is φ = 64580964.

The previous prime is 66118621. The next prime is 66118699. The reversal of 66118649 is 94681166.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 66118649 - 2¹² = 66114553 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (66118699) by changing a digit.

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 3 ways as a sum of consecutive naturals, for example, 768779 + ... + 768864.

It is an arithmetic number, because the mean of its divisors is an integer number (16914084).

Almost surely, 2^66118649 is an apocalyptic number.

It is an amenable number.

66118649 is a deficient number, since it is larger than the sum of its proper divisors (1537687).

66118649 is a wasteful number, since it uses less digits than its factorization.

66118649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1537686.

The product of its digits is 62208, while the sum is 41.

The square root of 66118649 is about 8131.3374668624. The cubic root of 66118649 is about 404.3660232976.

The spelling of 66118649 in words is "sixty-six million, one hundred eighteen thousand, six hundred forty-nine".