2661604305549 has 16 divisors (see below), whose sum is σ = 4060143765120. Its totient is φ = 1519279580160.

The previous prime is 2661604305541. The next prime is 2661604305587. The reversal of 2661604305549 is 9455034061662.

It is not a de Polignac number, because 2661604305549 - 2³ = 2661604305541 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2661604305541) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 68195272 + ... + 68234289.

It is an arithmetic number, because the mean of its divisors is an integer number (253758985320).

Almost surely, 2^{2661604305549} is an apocalyptic number.

It is an amenable number.

2661604305549 is a deficient number, since it is larger than the sum of its proper divisors (1398539459571).

2661604305549 is a wasteful number, since it uses less digits than its factorization.

2661604305549 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 136430500.

The product of its (nonzero) digits is 4665600, while the sum is 51.

The spelling of 2661604305549 in words is "two trillion, six hundred sixty-one billion, six hundred four million, three hundred five thousand, five hundred forty-nine".