261471643 has 4 divisors (see below), whose sum is σ = 261896040. Its totient is φ = 261047248.

The previous prime is 261471641. The next prime is 261471647. The reversal of 261471643 is 346174162.

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

It is a cyclic number.

It is not a de Polignac number, because 261471643 - 2¹ = 261471641 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 261471599 and 261471608.

It is not an unprimeable number, because it can be changed into a prime (261471641) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 211273 + ... + 212506.

It is an arithmetic number, because the mean of its divisors is an integer number (65474010).

Almost surely, 2^261471643 is an apocalyptic number.

261471643 is a deficient number, since it is larger than the sum of its proper divisors (424397).

261471643 is an equidigital number, since it uses as much as digits as its factorization.

261471643 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424396.

The product of its digits is 24192, while the sum is 34.

The square root of 261471643 is about 16170.0848173409. The cubic root of 261471643 is about 639.4523660079.

The spelling of 261471643 in words is "two hundred sixty-one million, four hundred seventy-one thousand, six hundred forty-three".