66505207 has 16 divisors (see below), whose sum is σ = 73258560. Its totient is φ = 60092928.

The previous prime is 66505181. The next prime is 66505217. The reversal of 66505207 is 70250566.

It is a cyclic number.

It is not a de Polignac number, because 66505207 - 2⁷ = 66505079 is a prime.

It is a super-2 number, since 2×66505207² = 8845885116225698, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66505217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 136318 + ... + 136804.

It is an arithmetic number, because the mean of its divisors is an integer number (4578660).

Almost surely, 2^66505207 is an apocalyptic number.

66505207 is a deficient number, since it is larger than the sum of its proper divisors (6753353).

66505207 is a wasteful number, since it uses less digits than its factorization.

66505207 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 810.

The product of its (nonzero) digits is 12600, while the sum is 31.

The square root of 66505207 is about 8155.0724705548. The cubic root of 66505207 is about 405.1525249827.

The spelling of 66505207 in words is "sixty-six million, five hundred five thousand, two hundred seven".