3661961 has 4 divisors (see below), whose sum is σ = 3667092. Its totient is φ = 3656832.

The previous prime is 3661951. The next prime is 3661963. The reversal of 3661961 is 1691663.

3661961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1691663 = 43 ⋅39341.

It can be written as a sum of positive squares in 2 ways, for example, as 2325625 + 1336336 = 1525^2 + 1156^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-3661961 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (3661963) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1280 + ... + 2993.

It is an arithmetic number, because the mean of its divisors is an integer number (916773).

Almost surely, 2^3661961 is an apocalyptic number.

It is an amenable number.

3661961 is a deficient number, since it is larger than the sum of its proper divisors (5131).

3661961 is an equidigital number, since it uses as much as digits as its factorization.

3661961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5130.

The product of its digits is 5832, while the sum is 32.

The square root of 3661961 is about 1913.6250938990. The cubic root of 3661961 is about 154.1361729153.

The spelling of 3661961 in words is "three million, six hundred sixty-one thousand, nine hundred sixty-one".