261516800 has 60 divisors (see below), whose sum is σ = 647960016. Its totient is φ = 104601600.

The previous prime is 261516793. The next prime is 261516839. The reversal of 261516800 is 8615162.

It is a happy number.

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 5 ways as a sum of consecutive naturals, for example, 2585 + ... + 23015.

Almost surely, 2^261516800 is an apocalyptic number.

261516800 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 261516800, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (323980008).

261516800 is an abundant number, since it is smaller than the sum of its proper divisors (386443216).

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

261516800 is an equidigital number, since it uses as much as digits as its factorization.

261516800 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20459 (or 20438 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 261516800 is about 16171.4810700814. The cubic root of 261516800 is about 639.4891757208.

The spelling of 261516800 in words is "two hundred sixty-one million, five hundred sixteen thousand, eight hundred".