261630659 has 2 divisors, whose sum is σ = 261630660. Its totient is φ = 261630658.

The previous prime is 261630653. The next prime is 261630661. The reversal of 261630659 is 956036162.

261630659 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261630659 is a prime.

Together with 261630661, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (261630653) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130815329 + 130815330.

It is an arithmetic number, because the mean of its divisors is an integer number (130815330).

Almost surely, 2^261630659 is an apocalyptic number.

261630659 is a deficient number, since it is larger than the sum of its proper divisors (1).

261630659 is an equidigital number, since it uses as much as digits as its factorization.

261630659 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 58320, while the sum is 38.

The square root of 261630659 is about 16175.0010510046. The cubic root of 261630659 is about 639.5819690375.

The spelling of 261630659 in words is "two hundred sixty-one million, six hundred thirty thousand, six hundred fifty-nine".