66501011 has 4 divisors (see below), whose sum is σ = 67302312. Its totient is φ = 65699712.

The previous prime is 66500939. The next prime is 66501049. The reversal of 66501011 is 11010566.

It is a happy number.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 66501011 - 2¹⁸ = 66238867 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (66501811) 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 3 ways as a sum of consecutive naturals, for example, 400526 + ... + 400691.

It is an arithmetic number, because the mean of its divisors is an integer number (16825578).

Almost surely, 2^66501011 is an apocalyptic number.

66501011 is a deficient number, since it is larger than the sum of its proper divisors (801301).

66501011 is an equidigital number, since it uses as much as digits as its factorization.

66501011 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 801300.

The product of its (nonzero) digits is 180, while the sum is 20.

The square root of 66501011 is about 8154.8152033017. The cubic root of 66501011 is about 405.1440040672.

Adding to 66501011 its reverse (11010566), we get a palindrome (77511577).

The spelling of 66501011 in words is "sixty-six million, five hundred one thousand, eleven".