66500101 has 2 divisors, whose sum is σ = 66500102. Its totient is φ = 66500100.

The previous prime is 66500099. The next prime is 66500123. The reversal of 66500101 is 10100566.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 48233025 + 18267076 = 6945^2 + 4274^2 .

It is a cyclic number.

It is not a de Polignac number, because 66500101 - 2¹ = 66500099 is a prime.

Together with 66500099, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (66500131) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 33250050 + 33250051.

It is an arithmetic number, because the mean of its divisors is an integer number (33250051).

Almost surely, 2^66500101 is an apocalyptic number.

It is an amenable number.

66500101 is a deficient number, since it is larger than the sum of its proper divisors (1).

66500101 is an equidigital number, since it uses as much as digits as its factorization.

66500101 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 180, while the sum is 19.

The square root of 66500101 is about 8154.7594078550. The cubic root of 66500101 is about 405.1421560615.

Adding to 66500101 its reverse (10100566), we get a palindrome (76600667).

The spelling of 66500101 in words is "sixty-six million, five hundred thousand, one hundred one".