66505513 has 16 divisors (see below), whose sum is σ = 72285696. Its totient is φ = 60952320.

The previous prime is 66505499. The next prime is 66505519. The reversal of 66505513 is 31550566.

It is a cyclic number.

It is not a de Polignac number, because 66505513 - 2⁹ = 66505001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66505519) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 200758 + ... + 201088.

It is an arithmetic number, because the mean of its divisors is an integer number (4517856).

Almost surely, 2^66505513 is an apocalyptic number.

It is an amenable number.

66505513 is a deficient number, since it is larger than the sum of its proper divisors (5780183).

66505513 is a wasteful number, since it uses less digits than its factorization.

66505513 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 624.

The product of its (nonzero) digits is 13500, while the sum is 31.

The square root of 66505513 is about 8155.0912318625. The cubic root of 66505513 is about 405.1531463700.

The spelling of 66505513 in words is "sixty-six million, five hundred five thousand, five hundred thirteen".