2661441641 has 4 divisors (see below), whose sum is σ = 2661553284. Its totient is φ = 2661330000.

The previous prime is 2661441623. The next prime is 2661441677. The reversal of 2661441641 is 1461441662.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It can be written as a sum of positive squares in 2 ways, for example, as 1269853225 + 1391588416 = 35635^2 + 37304^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2661441641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2661441611) 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, 4070 + ... + 73071.

It is an arithmetic number, because the mean of its divisors is an integer number (665388321).

Almost surely, 2^2661441641 is an apocalyptic number.

It is an amenable number.

2661441641 is a deficient number, since it is larger than the sum of its proper divisors (111643).

2661441641 is an equidigital number, since it uses as much as digits as its factorization.

2661441641 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111642.

The product of its digits is 27648, while the sum is 35.

The square root of 2661441641 is about 51589.1620497949. The cubic root of 2661441641 is about 1385.8162488996.

The spelling of 2661441641 in words is "two billion, six hundred sixty-one million, four hundred forty-one thousand, six hundred forty-one".