261530237 has 2 divisors, whose sum is σ = 261530238. Its totient is φ = 261530236.

The previous prime is 261530189. The next prime is 261530239. The reversal of 261530237 is 732035162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 151930276 + 109599961 = 12326^2 + 10469^2 .

It is a cyclic number.

It is not a de Polignac number, because 261530237 - 2⁶ = 261530173 is a prime.

Together with 261530239, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (261530239) 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 as a sum of consecutive naturals, namely, 130765118 + 130765119.

It is an arithmetic number, because the mean of its divisors is an integer number (130765119).

Almost surely, 2^261530237 is an apocalyptic number.

It is an amenable number.

261530237 is a deficient number, since it is larger than the sum of its proper divisors (1).

261530237 is an equidigital number, since it uses as much as digits as its factorization.

261530237 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7560, while the sum is 29.

The square root of 261530237 is about 16171.8965183432. The cubic root of 261530237 is about 639.5001280687.

Adding to 261530237 its reverse (732035162), we get a palindrome (993565399).

The spelling of 261530237 in words is "two hundred sixty-one million, five hundred thirty thousand, two hundred thirty-seven".