261604480 has 64 divisors (see below), whose sum is σ = 629772480. Its totient is φ = 103910400.

The previous prime is 261604459. The next prime is 261604481. The reversal of 261604480 is 84406162.

It is a tau number, because it is divible by the number of its divisors (64).

It is not an unprimeable number, because it can be changed into a prime (261604481) 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 7 ways as a sum of consecutive naturals, for example, 95287 + ... + 97993.

It is an arithmetic number, because the mean of its divisors is an integer number (9840195).

Almost surely, 2^261604480 is an apocalyptic number.

261604480 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 261604480, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (314886240).

261604480 is an abundant number, since it is smaller than the sum of its proper divisors (368168000).

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

261604480 is a wasteful number, since it uses less digits than its factorization.

261604480 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2877 (or 2865 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 261604480 is about 16174.1917881544. The cubic root of 261604480 is about 639.5606359428.

The spelling of 261604480 in words is "two hundred sixty-one million, six hundred four thousand, four hundred eighty".