5661439261 has 4 divisors (see below), whose sum is σ = 5677661500. Its totient is φ = 5645217024.

The previous prime is 5661439249. The next prime is 5661439271. The reversal of 5661439261 is 1629341665.

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 3286728900 + 2374710361 = 57330^2 + 48731^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-5661439261 is a prime.

It is a super-2 number, since 2×5661439261² = 64103789011984452242, 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 (5661439271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 8110596 + ... + 8111293.

It is an arithmetic number, because the mean of its divisors is an integer number (1419415375).

Almost surely, 2^5661439261 is an apocalyptic number.

It is an amenable number.

5661439261 is a deficient number, since it is larger than the sum of its proper divisors (16222239).

5661439261 is a wasteful number, since it uses less digits than its factorization.

5661439261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16222238.

The product of its digits is 233280, while the sum is 43.

The square root of 5661439261 is about 75242.5362477901. The cubic root of 5661439261 is about 1782.2787023210.

The spelling of 5661439261 in words is "five billion, six hundred sixty-one million, four hundred thirty-nine thousand, two hundred sixty-one".