66506505 has 16 divisors (see below), whose sum is σ = 114596160. Its totient is φ = 32741568.

The previous prime is 66506497. The next prime is 66506507. The reversal of 66506505 is 50560566.

It is not a de Polignac number, because 66506505 - 2³ = 66506497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (66506507) 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, 170335 + ... + 170724.

It is an arithmetic number, because the mean of its divisors is an integer number (7162260).

Almost surely, 2^66506505 is an apocalyptic number.

66506505 is a gapful number since it is divisible by the number (65) formed by its first and last digit.

It is an amenable number.

66506505 is a deficient number, since it is larger than the sum of its proper divisors (48089655).

66506505 is a wasteful number, since it uses less digits than its factorization.

66506505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 341080.

The product of its (nonzero) digits is 27000, while the sum is 33.

The square root of 66506505 is about 8155.1520525371. The cubic root of 66506505 is about 405.1551607891.

The spelling of 66506505 in words is "sixty-six million, five hundred six thousand, five hundred five".