2141664561 has 12 divisors (see below), whose sum is σ = 3168967620. Its totient is φ = 1392952320.

The previous prime is 2141664517. The next prime is 2141664589. The reversal of 2141664561 is 1654661412.

2141664561 is a `hidden beast` number, since 2 + 1 + 4 + 1 + 6 + 645 + 6 + 1 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 28515600 + 2113148961 = 5340^2 + 45969^2 .

It is not a de Polignac number, because 2141664561 - 2¹¹ = 2141662513 is a prime.

It is not an unprimeable number, because it can be changed into a prime (2141664361) 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 11 ways as a sum of consecutive naturals, for example, 2901616 + ... + 2902353.

It is an arithmetic number, because the mean of its divisors is an integer number (264080635).

Almost surely, 2^2141664561 is an apocalyptic number.

It is an amenable number.

2141664561 is a deficient number, since it is larger than the sum of its proper divisors (1027303059).

2141664561 is a wasteful number, since it uses less digits than its factorization.

2141664561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5804016 (or 5804013 counting only the distinct ones).

The product of its digits is 34560, while the sum is 36.

The square root of 2141664561 is about 46278.1218395907. The cubic root of 2141664561 is about 1288.9927760564.

The spelling of 2141664561 in words is "two billion, one hundred forty-one million, six hundred sixty-four thousand, five hundred sixty-one".