261331510205 has 8 divisors (see below), whose sum is σ = 313626788352. Its totient is φ = 209045890768.

The previous prime is 261331510199. The next prime is 261331510211. The reversal of 261331510205 is 502015133162.

It is an interprime number because it is at equal distance from previous prime (261331510199) and next prime (261331510211).

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

It is a cyclic number.

It is not a de Polignac number, because 261331510205 - 2⁴ = 261331510189 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2355017 + ... + 2463486.

It is an arithmetic number, because the mean of its divisors is an integer number (39203348544).

Almost surely, 2^261331510205 is an apocalyptic number.

It is an amenable number.

261331510205 is a deficient number, since it is larger than the sum of its proper divisors (52295278147).

261331510205 is a wasteful number, since it uses less digits than its factorization.

261331510205 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4829355.

The product of its (nonzero) digits is 5400, while the sum is 29.

Adding to 261331510205 its reverse (502015133162), we get a palindrome (763346643367).

The spelling of 261331510205 in words is "two hundred sixty-one billion, three hundred thirty-one million, five hundred ten thousand, two hundred five".