666511101 has 12 divisors (see below), whose sum is σ = 970089120. Its totient is φ = 440948040.

The previous prime is 666511099. The next prime is 666511103. The reversal of 666511101 is 101115666.

It is an interprime number because it is at equal distance from previous prime (666511099) and next prime (666511103).

It is not a de Polignac number, because 666511101 - 2¹ = 666511099 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (666511103) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 281481 + ... + 283838.

It is an arithmetic number, because the mean of its divisors is an integer number (80840760).

Almost surely, 2^666511101 is an apocalyptic number.

It is an amenable number.

666511101 is a deficient number, since it is larger than the sum of its proper divisors (303578019).

666511101 is a wasteful number, since it uses less digits than its factorization.

666511101 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 565456 (or 565453 counting only the distinct ones).

The product of its (nonzero) digits is 1080, while the sum is 27.

The square root of 666511101 is about 25816.8762827729. The cubic root of 666511101 is about 873.5125098866.

Adding to 666511101 its reverse (101115666), we get a palindrome (767626767).

It can be divided in two parts, 6665 and 11101, that added together give a triangular number (17766 = T₁₈₈).

The spelling of 666511101 in words is "six hundred sixty-six million, five hundred eleven thousand, one hundred one".