261445211 has 4 divisors (see below), whose sum is σ = 261478152. Its totient is φ = 261412272.

The previous prime is 261445141. The next prime is 261445271. The reversal of 261445211 is 112544162.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 261445211 - 2¹⁰ = 261444187 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261445271) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3536 + ... + 23138.

It is an arithmetic number, because the mean of its divisors is an integer number (65369538).

Almost surely, 2^261445211 is an apocalyptic number.

261445211 is a deficient number, since it is larger than the sum of its proper divisors (32941).

261445211 is a wasteful number, since it uses less digits than its factorization.

261445211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32940.

The product of its digits is 1920, while the sum is 26.

The square root of 261445211 is about 16169.2674849543. The cubic root of 261445211 is about 639.4308180058.

Adding to 261445211 its reverse (112544162), we get a palindrome (373989373).

The spelling of 261445211 in words is "two hundred sixty-one million, four hundred forty-five thousand, two hundred eleven".