261506880 has 392 divisors, whose sum is σ = 999439200. Its totient is φ = 64945152.

The previous prime is 261506867. The next prime is 261506911. The reversal of 261506880 is 88605162.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 55 ways as a sum of consecutive naturals, for example, 4432291 + ... + 4432349.

Almost surely, 2^261506880 is an apocalyptic number.

261506880 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 261506880, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (499719600).

261506880 is an abundant number, since it is smaller than the sum of its proper divisors (737932320).

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

261506880 is an equidigital number, since it uses as much as digits as its factorization.

261506880 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 113 (or 88 counting only the distinct ones).

The product of its (nonzero) digits is 23040, while the sum is 36.

The square root of 261506880 is about 16171.1743543875. The cubic root of 261506880 is about 639.4810897994.

The spelling of 261506880 in words is "two hundred sixty-one million, five hundred six thousand, eight hundred eighty".