261111760 has 240 divisors, whose sum is σ = 784235520. Its totient is φ = 79073280.

The previous prime is 261111713. The next prime is 261111787. The reversal of 261111760 is 67111162.

It is a happy number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 2933796 + ... + 2933884.

It is an arithmetic number, because the mean of its divisors is an integer number (3267648).

Almost surely, 2^261111760 is an apocalyptic number.

261111760 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261111760, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (392117760).

261111760 is an abundant number, since it is smaller than the sum of its proper divisors (523123760).

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

261111760 is a wasteful number, since it uses less digits than its factorization.

261111760 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 166 (or 147 counting only the distinct ones).

The product of its (nonzero) digits is 504, while the sum is 25.

The square root of 261111760 is about 16158.9529363755. The cubic root of 261111760 is about 639.1588559166.

The spelling of 261111760 in words is "two hundred sixty-one million, one hundred eleven thousand, seven hundred sixty".