261136543 has 4 divisors (see below), whose sum is σ = 262028088. Its totient is φ = 260245000.

The previous prime is 261136523. The next prime is 261136553. The reversal of 261136543 is 345631162.

261136543 is nontrivially palindromic in base 16.

261136543 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261136543 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 (261136523) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 445333 + ... + 445918.

It is an arithmetic number, because the mean of its divisors is an integer number (65507022).

Almost surely, 2^261136543 is an apocalyptic number.

261136543 is a deficient number, since it is larger than the sum of its proper divisors (891545).

261136543 is an equidigital number, since it uses as much as digits as its factorization.

261136543 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 891544.

The product of its digits is 12960, while the sum is 31.

The square root of 261136543 is about 16159.7197686099. The cubic root of 261136543 is about 639.1790768529.

The spelling of 261136543 in words is "two hundred sixty-one million, one hundred thirty-six thousand, five hundred forty-three".