66161201111 has 4 divisors (see below), whose sum is σ = 66161716824. Its totient is φ = 66160685400.

The previous prime is 66161201089. The next prime is 66161201123. The reversal of 66161201111 is 11110216166.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-66161201111 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 (66161201191) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 101741 + ... + 377721.

It is an arithmetic number, because the mean of its divisors is an integer number (16540429206).

Almost surely, 2^66161201111 is an apocalyptic number.

66161201111 is a deficient number, since it is larger than the sum of its proper divisors (515713).

66161201111 is a wasteful number, since it uses less digits than its factorization.

66161201111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515712.

The product of its (nonzero) digits is 432, while the sum is 26.

Adding to 66161201111 its reverse (11110216166), we get a palindrome (77271417277).

The spelling of 66161201111 in words is "sixty-six billion, one hundred sixty-one million, two hundred one thousand, one hundred eleven".