261823104 has 80 divisors (see below), whose sum is σ = 779212170. Its totient is φ = 87270912.

The previous prime is 261823043. The next prime is 261823109. The reversal of 261823104 is 401328162.

It can be written as a sum of positive squares in only one way, i.e., 158760000 + 103063104 = 12600^2 + 10152^2 .

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (261823109) by changing a digit.

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 9 ways as a sum of consecutive naturals, for example, 2259 + ... + 22994.

Almost surely, 2^261823104 is an apocalyptic number.

261823104 is a gapful number since it is divisible by the number (24) 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 261823104, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (389606085).

261823104 is an abundant number, since it is smaller than the sum of its proper divisors (517389066).

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

261823104 is an equidigital number, since it uses as much as digits as its factorization.

261823104 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 25279 (or 25258 counting only the distinct ones).

The product of its (nonzero) digits is 2304, while the sum is 27.

The square root of 261823104 is about 16180.9487978919. The cubic root of 261823104 is about 639.7387475361.

The spelling of 261823104 in words is "two hundred sixty-one million, eight hundred twenty-three thousand, one hundred four".