261123361 has 8 divisors (see below), whose sum is σ = 265288320. Its totient is φ = 256980048.

The previous prime is 261123311. The next prime is 261123367. The reversal of 261123361 is 163321162.

261123361 = 493² + 494² + ... + 966².

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 261123361 - 2²⁷ = 126905633 is a prime.

It is not an unprimeable number, because it can be changed into a prime (261123367) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 19830 + ... + 30256.

It is an arithmetic number, because the mean of its divisors is an integer number (33161040).

Almost surely, 2^261123361 is an apocalyptic number.

It is an amenable number.

261123361 is a deficient number, since it is larger than the sum of its proper divisors (4164959).

261123361 is a wasteful number, since it uses less digits than its factorization.

261123361 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 10823.

The product of its digits is 1296, while the sum is 25.

The square root of 261123361 is about 16159.3118974788. The cubic root of 261123361 is about 639.1683215595.

The spelling of 261123361 in words is "two hundred sixty-one million, one hundred twenty-three thousand, three hundred sixty-one".