261554567543117 has 32 divisors (see below), whose sum is σ = 266290127769600. Its totient is φ = 256863437107200.

The previous prime is 261554567543077. The next prime is 261554567543119. The reversal of 261554567543117 is 711345765455162.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261554567543117 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261554567543117.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261554567543119) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52092124067 + ... + 52092129087.

It is an arithmetic number, because the mean of its divisors is an integer number (8321566492800).

Almost surely, 2^{261554567543117} is an apocalyptic number.

It is an amenable number.

261554567543117 is a deficient number, since it is larger than the sum of its proper divisors (4735560226483).

261554567543117 is a wasteful number, since it uses less digits than its factorization.

261554567543117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9437.

The product of its digits is 105840000, while the sum is 62.

The spelling of 261554567543117 in words is "two hundred sixty-one trillion, five hundred fifty-four billion, five hundred sixty-seven million, five hundred forty-three thousand, one hundred seventeen".