261435600 has 150 divisors (see below), whose sum is σ = 938387670. Its totient is φ = 69707520.

The previous prime is 261435589. The next prime is 261435607. The reversal of 261435600 is 6534162.

261435600 is a `hidden beast` number, since 2 + 61 + 43 + 560 + 0 = 666.

It can be written as a sum of positive squares in 3 ways, for example, as 3640464 + 257795136 = 1908^2 + 16056^2 .

It is a tau number, because it is divible by the number of its divisors (150).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261435607) 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 29 ways as a sum of consecutive naturals, for example, 28366 + ... + 36434.

Almost surely, 2^261435600 is an apocalyptic number.

261435600 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 261435600, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (469193835).

261435600 is an abundant number, since it is smaller than the sum of its proper divisors (676952070).

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

261435600 is a wasteful number, since it uses less digits than its factorization.

261435600 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8099 (or 8079 counting only the distinct ones).

The product of its (nonzero) digits is 4320, while the sum is 27.

The square root of 261435600 is about 16168.9702826123. The cubic root of 261435600 is about 639.4229825274.

Adding to 261435600 its reverse (6534162), we get a palindrome (267969762).

The spelling of 261435600 in words is "two hundred sixty-one million, four hundred thirty-five thousand, six hundred".