66399708 has 24 divisors (see below), whose sum is σ = 156119040. Its totient is φ = 21963760.

The previous prime is 66399703. The next prime is 66399709. The reversal of 66399708 is 80799366.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66399703) 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 7 ways as a sum of consecutive naturals, for example, 19548 + ... + 22691.

It is an arithmetic number, because the mean of its divisors is an integer number (6504960).

Almost surely, 2^66399708 is an apocalyptic number.

It is an amenable number.

66399708 is an abundant number, since it is smaller than the sum of its proper divisors (89719332).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

66399708 is a wasteful number, since it uses less digits than its factorization.

66399708 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42377 (or 42375 counting only the distinct ones).

The product of its (nonzero) digits is 489888, while the sum is 48.

The square root of 66399708 is about 8148.6015978203. The cubic root of 66399708 is about 404.9381768153.

The spelling of 66399708 in words is "sixty-six million, three hundred ninety-nine thousand, seven hundred eight".