261818496 has 192 divisors, whose sum is σ = 827026200. Its totient is φ = 79134720.

The previous prime is 261818489. The next prime is 261818551. The reversal of 261818496 is 694818162.

It can be written as a sum of positive squares in 4 ways, for example, as 235192896 + 26625600 = 15336^2 + 5160^2 .

It is a tau number, because it is divible by the number of its divisors (192).

It is a nude number because it is divisible by every one of its digits.

Its product of digits (165888) is a multiple of the sum of its prime divisors (512).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 567706 + ... + 568166.

Almost surely, 2^261818496 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261818496, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (413513100).

261818496 is an abundant number, since it is smaller than the sum of its proper divisors (565207704).

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

261818496 is a wasteful number, since it uses less digits than its factorization.

261818496 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 527 (or 512 counting only the distinct ones).

The product of its digits is 165888, while the sum is 45.

The square root of 261818496 is about 16180.8064075929. The cubic root of 261818496 is about 639.7349944507.

It can be divided in two parts, 261 and 818496, that multiplied together give a square (213627456 = 14616²).

The spelling of 261818496 in words is "two hundred sixty-one million, eight hundred eighteen thousand, four hundred ninety-six".