5166665561 has 4 divisors (see below), whose sum is σ = 5333332224. Its totient is φ = 4999998900.

The previous prime is 5166665557. The next prime is 5166665579. The reversal of 5166665561 is 1655666615.

5166665561 is digitally balanced in base 3, 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 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 5166665561 - 2² = 5166665557 is a prime.

It is a super-3 number, since 3×5166665561³ (a number of 30 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (5166665501) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 83333285 + ... + 83333346.

It is an arithmetic number, because the mean of its divisors is an integer number (1333333056).

Almost surely, 2^5166665561 is an apocalyptic number.

It is an amenable number.

5166665561 is a deficient number, since it is larger than the sum of its proper divisors (166666663).

5166665561 is a wasteful number, since it uses less digits than its factorization.

5166665561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166666662.

The product of its digits is 972000, while the sum is 47.

The square root of 5166665561 is about 71879.5211517161. The cubic root of 5166665561 is about 1728.7682725614.

The spelling of 5166665561 in words is "five billion, one hundred sixty-six million, six hundred sixty-five thousand, five hundred sixty-one".