2113813 has 4 divisors (see below), whose sum is σ = 2276428. Its totient is φ = 1951200.

The previous prime is 2113801. The next prime is 2113819. The reversal of 2113813 is 3183112.

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 1205604 + 908209 = 1098^2 + 953^2 .

It is a cyclic number.

It is not a de Polignac number, because 2113813 - 2¹⁷ = 1982741 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 (2113819) 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, 81288 + ... + 81313.

It is an arithmetic number, because the mean of its divisors is an integer number (569107).

2^2113813 is an apocalyptic number.

It is an amenable number.

2113813 is a deficient number, since it is larger than the sum of its proper divisors (162615).

2113813 is a wasteful number, since it uses less digits than its factorization.

2113813 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 162614.

The product of its digits is 144, while the sum is 19.

The square root of 2113813 is about 1453.8958009431. The cubic root of 2113813 is about 128.3380751982.

Adding to 2113813 its reverse (3183112), we get a palindrome (5296925).

It can be divided in two parts, 2113 and 813, that added together give a triangular number (2926 = T₇₆).

The spelling of 2113813 in words is "two million, one hundred thirteen thousand, eight hundred thirteen".