5205510661 has 8 divisors (see below), whose sum is σ = 5638341240. Its totient is φ = 4777309632.

The previous prime is 5205510659. The next prime is 5205510677. The reversal of 5205510661 is 1660155025.

It can be written as a sum of positive squares in 4 ways, for example, as 1221502500 + 3984008161 = 34950^2 + 63119^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 5205510661 - 2¹ = 5205510659 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5205510601) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1155046 + ... + 1159543.

It is an arithmetic number, because the mean of its divisors is an integer number (704792655).

Almost surely, 2^5205510661 is an apocalyptic number.

It is an amenable number.

5205510661 is a deficient number, since it is larger than the sum of its proper divisors (432830579).

5205510661 is a wasteful number, since it uses less digits than its factorization.

5205510661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2314775.

The product of its (nonzero) digits is 9000, while the sum is 31.

The square root of 5205510661 is about 72149.2249507921. The cubic root of 5205510661 is about 1733.0899882205.

Adding to 5205510661 its reverse (1660155025), we get a palindrome (6865665686).

The spelling of 5205510661 in words is "five billion, two hundred five million, five hundred ten thousand, six hundred sixty-one".