261164543 has 2 divisors, whose sum is σ = 261164544. Its totient is φ = 261164542.

The previous prime is 261164531. The next prime is 261164567. The reversal of 261164543 is 345461162.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 261164543 - 2⁶ = 261164479 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261164513) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130582271 + 130582272.

It is an arithmetic number, because the mean of its divisors is an integer number (130582272).

Almost surely, 2^261164543 is an apocalyptic number.

261164543 is a deficient number, since it is larger than the sum of its proper divisors (1).

261164543 is an equidigital number, since it uses as much as digits as its factorization.

261164543 is an evil number, because the sum of its binary digits is even.

The product of its digits is 17280, while the sum is 32.

The square root of 261164543 is about 16160.5860970449. The cubic root of 261164543 is about 639.2019210634.

The spelling of 261164543 in words is "two hundred sixty-one million, one hundred sixty-four thousand, five hundred forty-three".