3611681 has 4 divisors (see below), whose sum is σ = 3709332. Its totient is φ = 3514032.

The previous prime is 3611677. The next prime is 3611711. The reversal of 3611681 is 1861163.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1861163 = 277 ⋅6719.

It can be written as a sum of positive squares in 2 ways, for example, as 3182656 + 429025 = 1784^2 + 655^2 .

It is a cyclic number.

It is not a de Polignac number, because 3611681 - 2² = 3611677 is a prime.

It is a super-2 number, since 2×3611681² = 26088479291522, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 3611681.

It is not an unprimeable number, because it can be changed into a prime (3611281) 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, 48770 + ... + 48843.

It is an arithmetic number, because the mean of its divisors is an integer number (927333).

Almost surely, 2^3611681 is an apocalyptic number.

It is an amenable number.

3611681 is a deficient number, since it is larger than the sum of its proper divisors (97651).

3611681 is an equidigital number, since it uses as much as digits as its factorization.

3611681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97650.

The product of its digits is 864, while the sum is 26.

The square root of 3611681 is about 1900.4423169357. The cubic root of 3611681 is about 153.4274715980.

It can be divided in two parts, 361 and 1681, that multiplied together give a square (606841 = 779²).

The spelling of 3611681 in words is "three million, six hundred eleven thousand, six hundred eighty-one".