2611681 has 4 divisors (see below), whose sum is σ = 2661012. Its totient is φ = 2562352.

The previous prime is 2611669. The next prime is 2611699. The reversal of 2611681 is 1861162.

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 1904400 + 707281 = 1380^2 + 841^2 .

It is a cyclic number.

It is not a de Polignac number, because 2611681 - 2²¹ = 514529 is a prime.

It is a super-2 number, since 2×2611681² = 13641755291522, which contains 22 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 (2611621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 24586 + ... + 24691.

It is an arithmetic number, because the mean of its divisors is an integer number (665253).

2^2611681 is an apocalyptic number.

It is an amenable number.

2611681 is a deficient number, since it is larger than the sum of its proper divisors (49331).

2611681 is an equidigital number, since it uses as much as digits as its factorization.

2611681 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49330.

The product of its digits is 576, while the sum is 25.

The square root of 2611681 is about 1616.0696148372. The cubic root of 2611681 is about 137.7125044658.

The spelling of 2611681 in words is "two million, six hundred eleven thousand, six hundred eighty-one".