261026489 has 2 divisors, whose sum is σ = 261026490. Its totient is φ = 261026488.

The previous prime is 261026429. The next prime is 261026501. The reversal of 261026489 is 984620162.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 213306025 + 47720464 = 14605^2 + 6908^2 .

It is a cyclic number.

It is not a de Polignac number, because 261026489 - 2¹² = 261022393 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (261026429) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130513244 + 130513245.

It is an arithmetic number, because the mean of its divisors is an integer number (130513245).

Almost surely, 2^261026489 is an apocalyptic number.

It is an amenable number.

261026489 is a deficient number, since it is larger than the sum of its proper divisors (1).

261026489 is an equidigital number, since it uses as much as digits as its factorization.

261026489 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 38.

The square root of 261026489 is about 16156.3142145726. The cubic root of 261026489 is about 639.0892718570.

The spelling of 261026489 in words is "two hundred sixty-one million, twenty-six thousand, four hundred eighty-nine".