261317530 has 16 divisors (see below), whose sum is σ = 471197160. Its totient is φ = 104343552.

The previous prime is 261317519. The next prime is 261317531. The reversal of 261317530 is 35713162.

It can be written as a sum of positive squares in 4 ways, for example, as 260144641 + 1172889 = 16129^2 + 1083^2 .

It is not an unprimeable number, because it can be changed into a prime (261317531) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 16875 + ... + 28414.

Almost surely, 2^261317530 is an apocalyptic number.

261317530 is a deficient number, since it is larger than the sum of its proper divisors (209879630).

261317530 is a wasteful number, since it uses less digits than its factorization.

261317530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45873.

The product of its (nonzero) digits is 3780, while the sum is 28.

The square root of 261317530 is about 16165.3187410580. The cubic root of 261317530 is about 639.3267089267.

The spelling of 261317530 in words is "two hundred sixty-one million, three hundred seventeen thousand, five hundred thirty".