66209101 has 16 divisors (see below), whose sum is σ = 80421120. Its totient is φ = 53210880.

The previous prime is 66209093. The next prime is 66209113. The reversal of 66209101 is 10190266.

It is a cyclic number.

It is not a de Polignac number, because 66209101 - 2³ = 66209093 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (66209131) 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, 36115 + ... + 37903.

It is an arithmetic number, because the mean of its divisors is an integer number (5026320).

Almost surely, 2^66209101 is an apocalyptic number.

It is an amenable number.

66209101 is a deficient number, since it is larger than the sum of its proper divisors (14212019).

66209101 is a wasteful number, since it uses less digits than its factorization.

66209101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2124.

The product of its (nonzero) digits is 648, while the sum is 25.

The square root of 66209101 is about 8136.8975045775. The cubic root of 66209101 is about 404.5503336242.

Adding to 66209101 its reverse (10190266), we get a palindrome (76399367).

The spelling of 66209101 in words is "sixty-six million, two hundred nine thousand, one hundred one".