261655544262045 has 32 divisors (see below), whose sum is σ = 425829719462400. Its totient is φ = 137156953004864.

The previous prime is 261655544262043. The next prime is 261655544262089. The reversal of 261655544262045 is 540262445556162.

It is a cyclic number.

It is not a de Polignac number, because 261655544262045 - 2¹ = 261655544262043 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261655544262043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (31) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 25120215 + ... + 33975524.

It is an arithmetic number, because the mean of its divisors is an integer number (13307178733200).

Almost surely, 2^{261655544262045} is an apocalyptic number.

It is an amenable number.

261655544262045 is a deficient number, since it is larger than the sum of its proper divisors (164174175200355).

261655544262045 is a wasteful number, since it uses less digits than its factorization.

261655544262045 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 59100809.

The product of its (nonzero) digits is 69120000, while the sum is 57.

The spelling of 261655544262045 in words is "two hundred sixty-one trillion, six hundred fifty-five billion, five hundred forty-four million, two hundred sixty-two thousand, forty-five".