261284587 has 2 divisors, whose sum is σ = 261284588. Its totient is φ = 261284586.

The previous prime is 261284567. The next prime is 261284633. The reversal of 261284587 is 785482162.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261284587 is a prime.

It is a super-3 number, since 3×261284587³ (a number of 26 digits) contains 333 as substring.

It is not a weakly prime, because it can be changed into another prime (261284537) 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, 130642293 + 130642294.

It is an arithmetic number, because the mean of its divisors is an integer number (130642294).

Almost surely, 2^261284587 is an apocalyptic number.

261284587 is a deficient number, since it is larger than the sum of its proper divisors (1).

261284587 is an equidigital number, since it uses as much as digits as its factorization.

261284587 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 215040, while the sum is 43.

The square root of 261284587 is about 16164.2997683166. The cubic root of 261284587 is about 639.2998422193.

The spelling of 261284587 in words is "two hundred sixty-one million, two hundred eighty-four thousand, five hundred eighty-seven".