12661111 has 4 divisors (see below), whose sum is σ = 12683632. Its totient is φ = 12638592.

The previous prime is 12661097. The next prime is 12661123. The reversal of 12661111 is 11116621.

12661111 is digitally balanced in base 2 and base 3, because in such bases it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 11116621 = 619 ⋅17959.

It is a cyclic number.

It is not a de Polignac number, because 12661111 - 2⁷ = 12660983 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 (12661171) 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, 10395 + ... + 11548.

It is an arithmetic number, because the mean of its divisors is an integer number (3170908).

Almost surely, 2^12661111 is an apocalyptic number.

12661111 is a deficient number, since it is larger than the sum of its proper divisors (22521).

12661111 is an equidigital number, since it uses as much as digits as its factorization.

12661111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22520.

The product of its digits is 72, while the sum is 19.

The square root of 12661111 is about 3558.2454946223. The cubic root of 12661111 is about 233.0722696974.

Adding to 12661111 its reverse (11116621), we get a palindrome (23777732).

The spelling of 12661111 in words is "twelve million, six hundred sixty-one thousand, one hundred eleven".