261123013 has 4 divisors (see below), whose sum is σ = 269546368. Its totient is φ = 252699660.

The previous prime is 261123011. The next prime is 261123029. The reversal of 261123013 is 310321162.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 261123013 - 2¹ = 261123011 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261123011) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 4211631 + ... + 4211692.

It is an arithmetic number, because the mean of its divisors is an integer number (67386592).

Almost surely, 2^261123013 is an apocalyptic number.

It is an amenable number.

261123013 is a deficient number, since it is larger than the sum of its proper divisors (8423355).

261123013 is an equidigital number, since it uses as much as digits as its factorization.

261123013 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8423354.

The product of its (nonzero) digits is 216, while the sum is 19.

The square root of 261123013 is about 16159.3011296900. The cubic root of 261123013 is about 639.1680376188.

Adding to 261123013 its reverse (310321162), we get a palindrome (571444175).

The spelling of 261123013 in words is "two hundred sixty-one million, one hundred twenty-three thousand, thirteen".