2166561061 has 8 divisors (see below), whose sum is σ = 2583725184. Its totient is φ = 1776310800.

The previous prime is 2166561043. The next prime is 2166561079. The reversal of 2166561061 is 1601656612.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (2166561043) and next prime (2166561079).

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 2166561061 - 2⁷ = 2166560933 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 (2166561031) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6728290 + ... + 6728611.

It is an arithmetic number, because the mean of its divisors is an integer number (322965648).

Almost surely, 2^2166561061 is an apocalyptic number.

It is an amenable number.

2166561061 is a deficient number, since it is larger than the sum of its proper divisors (417164123).

2166561061 is a wasteful number, since it uses less digits than its factorization.

2166561061 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13456931.

The product of its (nonzero) digits is 12960, while the sum is 34.

The square root of 2166561061 is about 46546.3324119097. The cubic root of 2166561061 is about 1293.9683222897.

The spelling of 2166561061 in words is "two billion, one hundred sixty-six million, five hundred sixty-one thousand, sixty-one".