261656234327543 has 96 divisors (see below), whose sum is σ = 303717058444800. Its totient is φ = 224810497612800.

The previous prime is 261656234327519. The next prime is 261656234327603. The reversal of 261656234327543 is 345723432656162.

It is not a de Polignac number, because 261656234327543 - 2¹² = 261656234323447 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261656234327443) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 122785655588 + ... + 122785657718.

It is an arithmetic number, because the mean of its divisors is an integer number (3163719358800).

Almost surely, 2^{261656234327543} is an apocalyptic number.

261656234327543 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

261656234327543 is a deficient number, since it is larger than the sum of its proper divisors (42060824117257).

261656234327543 is a wasteful number, since it uses less digits than its factorization.

261656234327543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3669 (or 3658 counting only the distinct ones).

The product of its digits is 130636800, while the sum is 59.

The spelling of 261656234327543 in words is "two hundred sixty-one trillion, six hundred fifty-six billion, two hundred thirty-four million, three hundred twenty-seven thousand, five hundred forty-three".