3111661 has 4 divisors (see below), whose sum is σ = 3556192. Its totient is φ = 2667132.

The previous prime is 3111659. The next prime is 3111673. The reversal of 3111661 is 1661113.

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, and also an emirpimes, since its reverse is a distinct semiprime: 1661113 = 19 ⋅87427.

It is a cyclic number.

It is not a de Polignac number, because 3111661 - 2¹ = 3111659 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 (3111631) 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, 222255 + ... + 222268.

It is an arithmetic number, because the mean of its divisors is an integer number (889048).

Almost surely, 2^3111661 is an apocalyptic number.

It is an amenable number.

3111661 is a deficient number, since it is larger than the sum of its proper divisors (444531).

3111661 is an equidigital number, since it uses as much as digits as its factorization.

3111661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 444530.

The product of its digits is 108, while the sum is 19.

The square root of 3111661 is about 1763.9900793372. The cubic root of 3111661 is about 145.9925717119.

Adding to 3111661 its reverse (1661113), we get a palindrome (4772774).

The spelling of 3111661 in words is "three million, one hundred eleven thousand, six hundred sixty-one".