261835680 has 192 divisors, whose sum is σ = 885282048. Its totient is φ = 64880640.

The previous prime is 261835631. The next prime is 261835681. The reversal of 261835680 is 86538162.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (261835681) 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, 408160 + ... + 408800.

It is an arithmetic number, because the mean of its divisors is an integer number (4610844).

Almost surely, 2^261835680 is an apocalyptic number.

261835680 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 261835680, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (442641024).

261835680 is an abundant number, since it is smaller than the sum of its proper divisors (623446368).

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

261835680 is a wasteful number, since it uses less digits than its factorization.

261835680 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 719 (or 711 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 39.

The square root of 261835680 is about 16181.3373983735. The cubic root of 261835680 is about 639.7489901077.

The spelling of 261835680 in words is "two hundred sixty-one million, eight hundred thirty-five thousand, six hundred eighty".