261600240 has 160 divisors (see below), whose sum is σ = 890942976. Its totient is φ = 62970880.

The previous prime is 261600221. The next prime is 261600253. The reversal of 261600240 is 42006162.

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 31 ways as a sum of consecutive naturals, for example, 519829 + ... + 520331.

Almost surely, 2^261600240 is an apocalyptic number.

261600240 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 261600240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (445471488).

261600240 is an abundant number, since it is smaller than the sum of its proper divisors (629342736).

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

261600240 is a wasteful number, since it uses less digits than its factorization.

261600240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 727 (or 721 counting only the distinct ones).

The product of its (nonzero) digits is 576, while the sum is 21.

The square root of 261600240 is about 16174.0607146134. The cubic root of 261600240 is about 639.5571806608.

The spelling of 261600240 in words is "two hundred sixty-one million, six hundred thousand, two hundred forty".