261728650 has 12 divisors (see below), whose sum is σ = 486815382. Its totient is φ = 104691440.

The previous prime is 261728641. The next prime is 261728669. The reversal of 261728650 is 56827162.

It is a happy number.

It can be written as a sum of positive squares in 3 ways, for example, as 135233641 + 126495009 = 11629^2 + 11247^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2617237 + ... + 2617336.

Almost surely, 2^261728650 is an apocalyptic number.

261728650 is a deficient number, since it is larger than the sum of its proper divisors (225086732).

261728650 is a wasteful number, since it uses less digits than its factorization.

261728650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5234585 (or 5234580 counting only the distinct ones).

The product of its (nonzero) digits is 40320, while the sum is 37.

The square root of 261728650 is about 16178.0298553316. The cubic root of 261728650 is about 639.6618086277.

The spelling of 261728650 in words is "two hundred sixty-one million, seven hundred twenty-eight thousand, six hundred fifty".