66513312 has 120 divisors (see below), whose sum is σ = 199051776. Its totient is φ = 21783168.

The previous prime is 66513311. The next prime is 66513313. The reversal of 66513312 is 21331566.

66513312 is a `hidden beast` number, since 6 + 651 + 3 + 3 + 1 + 2 = 666.

It is an interprime number because it is at equal distance from previous prime (66513311) and next prime (66513313).

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (66513311) by changing a digit.

It is a polite number, since it can be written in 19 ways as a sum of consecutive naturals, for example, 173473 + ... + 173855.

Almost surely, 2^66513312 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 66513312, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (99525888).

66513312 is an abundant number, since it is smaller than the sum of its proper divisors (132538464).

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

66513312 is a wasteful number, since it uses less digits than its factorization.

66513312 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 472 (or 455 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 66513312 is about 8155.5693853955. The cubic root of 66513312 is about 405.1689829814.

Adding to 66513312 its reverse (21331566), we get a palindrome (87844878).

The spelling of 66513312 in words is "sixty-six million, five hundred thirteen thousand, three hundred twelve".