261563350453543 has 16 divisors (see below), whose sum is σ = 265624447755744. Its totient is φ = 257530330552320.

The previous prime is 261563350453423. The next prime is 261563350453549. The reversal of 261563350453543 is 345354053365162.

It is a cyclic number.

It is not a de Polignac number, because 261563350453543 - 2¹⁷ = 261563350322471 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 (261563350453549) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (29) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 220825323 + ... + 222006643.

It is an arithmetic number, because the mean of its divisors is an integer number (16601527984734).

Almost surely, 2^{261563350453543} is an apocalyptic number.

261563350453543 is a deficient number, since it is larger than the sum of its proper divisors (4061097302201).

261563350453543 is a wasteful number, since it uses less digits than its factorization.

261563350453543 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1193202.

The product of its (nonzero) digits is 58320000, while the sum is 55.

The spelling of 261563350453543 in words is "two hundred sixty-one trillion, five hundred sixty-three billion, three hundred fifty million, four hundred fifty-three thousand, five hundred forty-three".