12311661 has 4 divisors (see below), whose sum is σ = 16415552. Its totient is φ = 8207772.

The previous prime is 12311657. The next prime is 12311671. The reversal of 12311661 is 16611321.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 12311661 - 2² = 12311657 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 (12311641) 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, 2051941 + ... + 2051946.

It is an arithmetic number, because the mean of its divisors is an integer number (4103888).

Almost surely, 2^12311661 is an apocalyptic number.

It is an amenable number.

12311661 is a deficient number, since it is larger than the sum of its proper divisors (4103891).

12311661 is an equidigital number, since it uses as much as digits as its factorization.

12311661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4103890.

The product of its digits is 216, while the sum is 21.

The square root of 12311661 is about 3508.7976573180. The cubic root of 12311661 is about 230.9079485559.

Adding to 12311661 its reverse (16611321), we get a palindrome (28922982).

The spelling of 12311661 in words is "twelve million, three hundred eleven thousand, six hundred sixty-one".