261299808 has 144 divisors (see below), whose sum is σ = 926505216. Its totient is φ = 67864320.

The previous prime is 261299791. The next prime is 261299813. The reversal of 261299808 is 808992162.

261299808 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 (144).

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 16285 + ... + 28067.

It is an arithmetic number, because the mean of its divisors is an integer number (6434064).

Almost surely, 2^261299808 is an apocalyptic number.

261299808 is a gapful number since it is divisible by the number (28) 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 261299808, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (463252608).

261299808 is an abundant number, since it is smaller than the sum of its proper divisors (665205408).

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

261299808 is a wasteful number, since it uses less digits than its factorization.

261299808 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 11817 (or 11806 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 45.

The square root of 261299808 is about 16164.7705829684. The cubic root of 261299808 is about 639.3122560067.

It can be divided in two parts, 26129 and 9808, that added together give a cube (35937 = 33³).

The spelling of 261299808 in words is "two hundred sixty-one million, two hundred ninety-nine thousand, eight hundred eight".