2131666 has 8 divisors (see below), whose sum is σ = 3209724. Its totient is φ = 1061760.

The previous prime is 2131651. The next prime is 2131669. The reversal of 2131666 is 6661312.

It can be written as a sum of positive squares in 2 ways, for example, as 2117025 + 14641 = 1455^2 + 121^2 .

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

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 2131666.

It is not an unprimeable number, because it can be changed into a prime (2131669) 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, 1335 + ... + 2458.

2^2131666 is an apocalyptic number.

2131666 is a deficient number, since it is larger than the sum of its proper divisors (1078058).

2131666 is a wasteful number, since it uses less digits than its factorization.

2131666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4076.

The product of its digits is 1296, while the sum is 25.

The square root of 2131666 is about 1460.0226025648. The cubic root of 2131666 is about 128.6983718599.

Adding to 2131666 its reverse (6661312), we get a palindrome (8792978).

The spelling of 2131666 in words is "two million, one hundred thirty-one thousand, six hundred sixty-six".