261008613 has 12 divisors (see below), whose sum is σ = 390013260. Its totient is φ = 168005376.

The previous prime is 261008611. The next prime is 261008621. The reversal of 261008613 is 316800162.

It can be written as a sum of positive squares in 2 ways, for example, as 126495009 + 134513604 = 11247^2 + 11598^2 .

It is not a de Polignac number, because 261008613 - 2¹ = 261008611 is a prime.

261008613 is a modest number, since divided by 8613 gives 261 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (261008611) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 499756 + ... + 500277.

It is an arithmetic number, because the mean of its divisors is an integer number (32501105).

Almost surely, 2^261008613 is an apocalyptic number.

It is an amenable number.

261008613 is a deficient number, since it is larger than the sum of its proper divisors (129004647).

261008613 is a wasteful number, since it uses less digits than its factorization.

261008613 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000068 (or 1000065 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 261008613 is about 16155.7609848623. The cubic root of 261008613 is about 639.0746825068.

Adding to 261008613 its reverse (316800162), we get a palindrome (577808775).

The spelling of 261008613 in words is "two hundred sixty-one million, eight thousand, six hundred thirteen".