261243155323 has 8 divisors (see below), whose sum is σ = 261859023728. Its totient is φ = 260627963904.

The previous prime is 261243155291. The next prime is 261243155339. The reversal of 261243155323 is 323551342162.

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 261243155323 - 2⁵ = 261243155291 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (261243155623) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 607636 + ... + 944302.

It is an arithmetic number, because the mean of its divisors is an integer number (32732377966).

Almost surely, 2^261243155323 is an apocalyptic number.

261243155323 is a deficient number, since it is larger than the sum of its proper divisors (615868405).

261243155323 is a wasteful number, since it uses less digits than its factorization.

261243155323 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 338493.

The product of its digits is 129600, while the sum is 37.

Adding to 261243155323 its reverse (323551342162), we get a palindrome (584794497485).

The spelling of 261243155323 in words is "two hundred sixty-one billion, two hundred forty-three million, one hundred fifty-five thousand, three hundred twenty-three".