261136013 has 2 divisors, whose sum is σ = 261136014. Its totient is φ = 261136012.

The previous prime is 261136009. The next prime is 261136021. The reversal of 261136013 is 310631162.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 166229449 + 94906564 = 12893^2 + 9742^2 .

It is a cyclic number.

It is not a de Polignac number, because 261136013 - 2² = 261136009 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 261136013.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261136313) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130568006 + 130568007.

It is an arithmetic number, because the mean of its divisors is an integer number (130568007).

Almost surely, 2^261136013 is an apocalyptic number.

It is an amenable number.

261136013 is a deficient number, since it is larger than the sum of its proper divisors (1).

261136013 is an equidigital number, since it uses as much as digits as its factorization.

261136013 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 648, while the sum is 23.

The square root of 261136013 is about 16159.7033698023. The cubic root of 261136013 is about 639.1786444288.

Adding to 261136013 its reverse (310631162), we get a palindrome (571767175).

The spelling of 261136013 in words is "two hundred sixty-one million, one hundred thirty-six thousand, thirteen".