261123366 has 64 divisors (see below), whose sum is σ = 653806080. Its totient is φ = 67791360.

The previous prime is 261123311. The next prime is 261123367. The reversal of 261123366 is 663321162.

261123366 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a nude number because it is divisible by every one of its digits.

It is a congruent number.

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

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 14401 + ... + 27011.

It is an arithmetic number, because the mean of its divisors is an integer number (10215720).

Almost surely, 2^261123366 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261123366, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (326903040).

261123366 is an abundant number, since it is smaller than the sum of its proper divisors (392682714).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

261123366 is a wasteful number, since it uses less digits than its factorization.

261123366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12669.

The product of its digits is 7776, while the sum is 30.

The square root of 261123366 is about 16159.3120521884. The cubic root of 261123366 is about 639.1683256391.

The spelling of 261123366 in words is "two hundred sixty-one million, one hundred twenty-three thousand, three hundred sixty-six".