261066330 has 192 divisors, whose sum is σ = 830269440. Its totient is φ = 55617408.

The previous prime is 261066319. The next prime is 261066343. The reversal of 261066330 is 33660162.

261066330 is a `hidden beast` number, since 26 + 1 + 0 + 6 + 633 + 0 = 666.

It is a junction number, because it is equal to n+sod(n) for n = 261066294 and 261066303.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 622861 + ... + 623279.

It is an arithmetic number, because the mean of its divisors is an integer number (4324320).

Almost surely, 2^261066330 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 261066330, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (415134720).

261066330 is an abundant number, since it is smaller than the sum of its proper divisors (569203110).

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

261066330 is a wasteful number, since it uses less digits than its factorization.

261066330 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 505 (or 502 counting only the distinct ones).

The product of its (nonzero) digits is 3888, while the sum is 27.

The square root of 261066330 is about 16157.5471529561. The cubic root of 261066330 is about 639.1217853648.

The spelling of 261066330 in words is "two hundred sixty-one million, sixty-six thousand, three hundred thirty".