261605120 has 216 divisors, whose sum is σ = 753573744. Its totient is φ = 86704128.

The previous prime is 261605119. The next prime is 261605159. The reversal of 261605120 is 21506162.

261605120 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2696912 + ... + 2697008.

Almost surely, 2^261605120 is an apocalyptic number.

261605120 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 261605120, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (376786872).

261605120 is an abundant number, since it is smaller than the sum of its proper divisors (491968624).

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

261605120 is an equidigital number, since it uses as much as digits as its factorization.

261605120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 175 (or 154 counting only the distinct ones).

The product of its (nonzero) digits is 720, while the sum is 23.

The square root of 261605120 is about 16174.2115727475. The cubic root of 261605120 is about 639.5611574916.

The spelling of 261605120 in words is "two hundred sixty-one million, six hundred five thousand, one hundred twenty".