2113561 has 4 divisors (see below), whose sum is σ = 2116624. Its totient is φ = 2110500.

The previous prime is 2113523. The next prime is 2113567. The reversal of 2113561 is 1653112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 2113561 - 2¹¹ = 2111513 is a prime.

It is a Duffinian number.

2113561 is a lucky number.

It is not an unprimeable number, because it can be changed into a prime (2113567) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (5) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 46 + ... + 2056.

It is an arithmetic number, because the mean of its divisors is an integer number (529156).

2^2113561 is an apocalyptic number.

It is an amenable number.

2113561 is a deficient number, since it is larger than the sum of its proper divisors (3063).

2113561 is a wasteful number, since it uses less digits than its factorization.

2113561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3062.

The product of its digits is 180, while the sum is 19.

The square root of 2113561 is about 1453.8091346528. The cubic root of 2113561 is about 128.3329750182.

Adding to 2113561 its reverse (1653112), we get a palindrome (3766673).

The spelling of 2113561 in words is "two million, one hundred thirteen thousand, five hundred sixty-one".