261332240 has 80 divisors (see below), whose sum is σ = 665582400. Its totient is φ = 94834176.

The previous prime is 261332231. The next prime is 261332257. The reversal of 261332240 is 42233162.

261332240 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 59231 + ... + 63489.

It is an arithmetic number, because the mean of its divisors is an integer number (8319780).

Almost surely, 2^261332240 is an apocalyptic number.

261332240 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 261332240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (332791200).

261332240 is an abundant number, since it is smaller than the sum of its proper divisors (404250160).

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

261332240 is a wasteful number, since it uses less digits than its factorization.

261332240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4344 (or 4338 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 23.

The square root of 261332240 is about 16165.7737210441. The cubic root of 261332240 is about 639.3387049575.

The spelling of 261332240 in words is "two hundred sixty-one million, three hundred thirty-two thousand, two hundred forty".