66618512 has 40 divisors (see below), whose sum is σ = 137341656. Its totient is φ = 31195136.

The previous prime is 66618469. The next prime is 66618523. The reversal of 66618512 is 21581666.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 36192256 + 30426256 = 6016^2 + 5516^2 .

It is a super-2 number, since 2×66618512² = 8876052282188288, which contains 22 as substring.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 69428 + ... + 70380.

Almost surely, 2^66618512 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 66618512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (68670828).

66618512 is an abundant number, since it is smaller than the sum of its proper divisors (70723144).

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

66618512 is a wasteful number, since it uses less digits than its factorization.

66618512 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1235 (or 1229 counting only the distinct ones).

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

The square root of 66618512 is about 8162.0164175282. The cubic root of 66618512 is about 405.3824807191.

The spelling of 66618512 in words is "sixty-six million, six hundred eighteen thousand, five hundred twelve".