2661543542164 has 18 divisors (see below), whose sum is σ = 5043546269790. Its totient is φ = 1228404711456.

The previous prime is 2661543542137. The next prime is 2661543542233. The reversal of 2661543542164 is 4612453451662.

It can be written as a sum of positive squares in 3 ways, for example, as 124085698564 + 2537457843600 = 352258^2 + 1592940^2 .

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 1968596619 + ... + 1968597970.

Almost surely, 2^{2661543542164} is an apocalyptic number.

It is an amenable number.

2661543542164 is a deficient number, since it is larger than the sum of its proper divisors (2382002727626).

2661543542164 is a wasteful number, since it uses less digits than its factorization.

2661543542164 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3937194619 (or 3937194604 counting only the distinct ones).

The product of its digits is 4147200, while the sum is 49.

The spelling of 2661543542164 in words is "two trillion, six hundred sixty-one billion, five hundred forty-three million, five hundred forty-two thousand, one hundred sixty-four".