2031661 has 4 divisors (see below), whose sum is σ = 2042172. Its totient is φ = 2021152.

The previous prime is 2031611. The next prime is 2031671. The reversal of 2031661 is 1661302.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1550025 + 481636 = 1245^2 + 694^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2031661 is a prime.

It is a super-3 number, since 3×2031661³ = 25157934753334373343, which contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2031611) 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, 4960 + ... + 5353.

It is an arithmetic number, because the mean of its divisors is an integer number (510543).

2^2031661 is an apocalyptic number.

It is an amenable number.

2031661 is a deficient number, since it is larger than the sum of its proper divisors (10511).

2031661 is a wasteful number, since it uses less digits than its factorization.

2031661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10510.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 2031661 is about 1425.3634624193. The cubic root of 2031661 is about 126.6534666146.

Adding to 2031661 its reverse (1661302), we get a palindrome (3692963).

The spelling of 2031661 in words is "two million, thirty-one thousand, six hundred sixty-one".