261730660 has 12 divisors (see below), whose sum is σ = 549634428. Its totient is φ = 104692256.

The previous prime is 261730633. The next prime is 261730661. The reversal of 261730660 is 66037162.

261730660 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 2 ways, for example, as 205750336 + 55980324 = 14344^2 + 7482^2 .

It is not an unprimeable number, because it can be changed into a prime (261730661) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 6543247 + ... + 6543286.

It is an arithmetic number, because the mean of its divisors is an integer number (45802869).

Almost surely, 2^261730660 is an apocalyptic number.

261730660 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

261730660 is an abundant number, since it is smaller than the sum of its proper divisors (287903768).

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

261730660 is a wasteful number, since it uses less digits than its factorization.

261730660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13086542 (or 13086540 counting only the distinct ones).

The product of its (nonzero) digits is 9072, while the sum is 31.

The square root of 261730660 is about 16178.0919764971. The cubic root of 261730660 is about 639.6634460958.

The spelling of 261730660 in words is "two hundred sixty-one million, seven hundred thirty thousand, six hundred sixty".