2231661 has 8 divisors (see below), whose sum is σ = 2983680. Its totient is φ = 1483712.

The previous prime is 2231653. The next prime is 2231681. The reversal of 2231661 is 1661322.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2231661 - 2³ = 2231653 is a prime.

It is a super-3 number, since 3×2231661³ = 33343096267392173343, which contains 333 as substring.

2231661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2231681) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 661 + ... + 2213.

It is an arithmetic number, because the mean of its divisors is an integer number (372960).

2^2231661 is an apocalyptic number.

It is an amenable number.

2231661 is a deficient number, since it is larger than the sum of its proper divisors (752019).

2231661 is a wasteful number, since it uses less digits than its factorization.

2231661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2035.

The product of its digits is 432, while the sum is 21.

The square root of 2231661 is about 1493.8744927202. The cubic root of 2231661 is about 130.6800848997.

Adding to 2231661 its reverse (1661322), we get a palindrome (3892983).

The spelling of 2231661 in words is "two million, two hundred thirty-one thousand, six hundred sixty-one".