261840366 has 12 divisors (see below), whose sum is σ = 567320832. Its totient is φ = 87280116.

The previous prime is 261840343. The next prime is 261840367. The reversal of 261840366 is 663048162.

261840366 is a `hidden beast` number, since 2 + 618 + 4 + 0 + 36 + 6 = 666.

It is a self number, because there is not a number n which added to its sum of digits gives 261840366.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261840367) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 7273326 + ... + 7273361.

It is an arithmetic number, because the mean of its divisors is an integer number (47276736).

Almost surely, 2^261840366 is an apocalyptic number.

261840366 is an abundant number, since it is smaller than the sum of its proper divisors (305480466).

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

261840366 is a wasteful number, since it uses less digits than its factorization.

261840366 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14546695 (or 14546692 counting only the distinct ones).

The product of its (nonzero) digits is 41472, while the sum is 36.

The square root of 261840366 is about 16181.4821941626. The cubic root of 261840366 is about 639.7528065546.

The spelling of 261840366 in words is "two hundred sixty-one million, eight hundred forty thousand, three hundred sixty-six".