66812516 has 24 divisors (see below), whose sum is σ = 129185280. Its totient is φ = 30073472.

The previous prime is 66812509. The next prime is 66812573. The reversal of 66812516 is 61521866.

It is a happy number.

It is an unprimeable number.

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, 19796 + ... + 22923.

It is an arithmetic number, because the mean of its divisors is an integer number (5382720).

Almost surely, 2^66812516 is an apocalyptic number.

It is an amenable number.

66812516 is a deficient number, since it is larger than the sum of its proper divisors (62372764).

66812516 is a wasteful number, since it uses less digits than its factorization.

66812516 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42763 (or 42761 counting only the distinct ones).

The product of its digits is 17280, while the sum is 35.

The square root of 66812516 is about 8173.8923408618. The cubic root of 66812516 is about 405.7756127007.

The spelling of 66812516 in words is "sixty-six million, eight hundred twelve thousand, five hundred sixteen".