2013661 has 4 divisors (see below), whose sum is σ = 2168572. Its totient is φ = 1858752.

The previous prime is 2013659. The next prime is 2013679. The reversal of 2013661 is 1663102.

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 308025 + 1705636 = 555^2 + 1306^2 .

It is a cyclic number.

It is not a de Polignac number, because 2013661 - 2¹ = 2013659 is a prime.

It is a Duffinian number.

2013661 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2013761) 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, 77436 + ... + 77461.

It is an arithmetic number, because the mean of its divisors is an integer number (542143).

2^2013661 is an apocalyptic number.

It is an amenable number.

2013661 is a deficient number, since it is larger than the sum of its proper divisors (154911).

2013661 is a wasteful number, since it uses less digits than its factorization.

2013661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 154910.

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

The square root of 2013661 is about 1419.0352356443. The cubic root of 2013661 is about 126.2783173418.

Adding to 2013661 its reverse (1663102), we get a palindrome (3676763).

The spelling of 2013661 in words is "two million, thirteen thousand, six hundred sixty-one".