66668737 has 4 divisors (see below), whose sum is σ = 66713220. Its totient is φ = 66624256.

The previous prime is 66668731. The next prime is 66668803. The reversal of 66668737 is 73786666.

66668737 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It can be written as a sum of positive squares in 2 ways, for example, as 1962801 + 64705936 = 1401^2 + 8044^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66668737 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66668731) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 19912 + ... + 23017.

It is an arithmetic number, because the mean of its divisors is an integer number (16678305).

Almost surely, 2^66668737 is an apocalyptic number.

It is an amenable number.

66668737 is a deficient number, since it is larger than the sum of its proper divisors (44483).

66668737 is a wasteful number, since it uses less digits than its factorization.

66668737 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 44482.

The product of its digits is 1524096, while the sum is 49.

The square root of 66668737 is about 8165.0925897996. The cubic root of 66668737 is about 405.4843303900.

The spelling of 66668737 in words is "sixty-six million, six hundred sixty-eight thousand, seven hundred thirty-seven".