5115561661 has 4 divisors (see below), whose sum is σ = 5846356192. Its totient is φ = 4384767132.

The previous prime is 5115561637. The next prime is 5115561673. The reversal of 5115561661 is 1661655115.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 5115561661 - 2⁷ = 5115561533 is a prime.

It is a super-2 number, since 2×5115561661² = 52337942214986157842, 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 5115561661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (5115561611) 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, 365397255 + ... + 365397268.

It is an arithmetic number, because the mean of its divisors is an integer number (1461589048).

Almost surely, 2^5115561661 is an apocalyptic number.

It is an amenable number.

5115561661 is a deficient number, since it is larger than the sum of its proper divisors (730794531).

5115561661 is an equidigital number, since it uses as much as digits as its factorization.

5115561661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 730794530.

The product of its digits is 27000, while the sum is 37.

The square root of 5115561661 is about 71523.1547192935. The cubic root of 5115561661 is about 1723.0495814082.

The spelling of 5115561661 in words is "five billion, one hundred fifteen million, five hundred sixty-one thousand, six hundred sixty-one".