261918160 has 160 divisors (see below), whose sum is σ = 726739200. Its totient is φ = 85929984.

The previous prime is 261918121. The next prime is 261918161. The reversal of 261918160 is 61819162.

It is a super-2 number, since 2×261918160² = 137202245075571200, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261918161) 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, 1757766 + ... + 1757914.

It is an arithmetic number, because the mean of its divisors is an integer number (4542120).

Almost surely, 2^261918160 is an apocalyptic number.

261918160 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 261918160, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (363369600).

261918160 is an abundant number, since it is smaller than the sum of its proper divisors (464821040).

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

261918160 is a wasteful number, since it uses less digits than its factorization.

261918160 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 285 (or 279 counting only the distinct ones).

The product of its (nonzero) digits is 5184, while the sum is 34.

The square root of 261918160 is about 16183.8858127460. The cubic root of 261918160 is about 639.8161581334.

The spelling of 261918160 in words is "two hundred sixty-one million, nine hundred eighteen thousand, one hundred sixty".