66649694 has 4 divisors (see below), whose sum is σ = 99974544. Its totient is φ = 33324846.

The previous prime is 66649679. The next prime is 66649711. The reversal of 66649694 is 49694666.

It is a happy number.

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

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 16662422 + ... + 16662425.

It is an arithmetic number, because the mean of its divisors is an integer number (24993636).

Almost surely, 2^66649694 is an apocalyptic number.

66649694 is a deficient number, since it is larger than the sum of its proper divisors (33324850).

66649694 is a wasteful number, since it uses less digits than its factorization.

66649694 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 33324849.

The product of its digits is 1679616, while the sum is 50.

The square root of 66649694 is about 8163.9263837935. The cubic root of 66649694 is about 405.4457197219.

The spelling of 66649694 in words is "sixty-six million, six hundred forty-nine thousand, six hundred ninety-four".