66720507 has 24 divisors (see below), whose sum is σ = 104271696. Its totient is φ = 37836288.

The previous prime is 66720491. The next prime is 66720553. The reversal of 66720507 is 70502766.

It is not a de Polignac number, because 66720507 - 2⁴ = 66720491 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66720107) by changing a digit.

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 23 ways as a sum of consecutive naturals, for example, 18483 + ... + 21795.

It is an arithmetic number, because the mean of its divisors is an integer number (4344654).

Almost surely, 2^66720507 is an apocalyptic number.

66720507 is a deficient number, since it is larger than the sum of its proper divisors (37551189).

66720507 is a wasteful number, since it uses less digits than its factorization.

66720507 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3467 (or 3460 counting only the distinct ones).

The product of its (nonzero) digits is 17640, while the sum is 33.

The square root of 66720507 is about 8168.2621774769. The cubic root of 66720507 is about 405.5892595941.

The spelling of 66720507 in words is "sixty-six million, seven hundred twenty thousand, five hundred seven".