66745816 has 16 divisors (see below), whose sum is σ = 130590000. Its totient is φ = 31921824.

The previous prime is 66745813. The next prime is 66745837. The reversal of 66745816 is 61854766.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66745813) 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, 181191 + ... + 181558.

It is an arithmetic number, because the mean of its divisors is an integer number (8161875).

Almost surely, 2^66745816 is an apocalyptic number.

It is an amenable number.

66745816 is a deficient number, since it is larger than the sum of its proper divisors (63844184).

66745816 is a wasteful number, since it uses less digits than its factorization.

66745816 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 362778 (or 362774 counting only the distinct ones).

The product of its digits is 241920, while the sum is 43.

The square root of 66745816 is about 8169.8112585298. The cubic root of 66745816 is about 405.6405369867.

The spelling of 66745816 in words is "sixty-six million, seven hundred forty-five thousand, eight hundred sixteen".