2181013 has 4 divisors (see below), whose sum is σ = 2200428. Its totient is φ = 2161600.

The previous prime is 2181007. The next prime is 2181017. The reversal of 2181013 is 3101812.

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 485809 + 1695204 = 697^2 + 1302^2 .

It is a cyclic number.

It is not a de Polignac number, because 2181013 - 2⁹ = 2180501 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 (2181017) 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, 9538 + ... + 9763.

It is an arithmetic number, because the mean of its divisors is an integer number (550107).

2^2181013 is an apocalyptic number.

It is an amenable number.

2181013 is a deficient number, since it is larger than the sum of its proper divisors (19415).

2181013 is a wasteful number, since it uses less digits than its factorization.

2181013 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 19414.

The product of its (nonzero) digits is 48, while the sum is 16.

The square root of 2181013 is about 1476.8253112674. The cubic root of 2181013 is about 129.6839066019.

Adding to 2181013 its reverse (3101812), we get a palindrome (5282825).

The spelling of 2181013 in words is "two million, one hundred eighty-one thousand, thirteen".