261123005 has 32 divisors (see below), whose sum is σ = 374226048. Its totient is φ = 172396800.

The previous prime is 261122993. The next prime is 261123011. The reversal of 261123005 is 500321162.

It is not a de Polignac number, because 261123005 - 2¹² = 261118909 is a prime.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 40622 + ... + 46608.

It is an arithmetic number, because the mean of its divisors is an integer number (11694564).

Almost surely, 2^261123005 is an apocalyptic number.

It is an amenable number.

261123005 is a deficient number, since it is larger than the sum of its proper divisors (113103043).

261123005 is a wasteful number, since it uses less digits than its factorization.

261123005 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6077.

The product of its (nonzero) digits is 360, while the sum is 20.

The square root of 261123005 is about 16159.3008821545. The cubic root of 261123005 is about 639.1680310914.

Adding to 261123005 its reverse (500321162), we get a palindrome (761444167).

The spelling of 261123005 in words is "two hundred sixty-one million, one hundred twenty-three thousand, five".