261887976587 has 2 divisors, whose sum is σ = 261887976588. Its totient is φ = 261887976586.

The previous prime is 261887976557. The next prime is 261887976613. The reversal of 261887976587 is 785679788162.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 261887976587 - 2¹⁴ = 261887960203 is a prime.

It is not a weakly prime, because it can be changed into another prime (261887976527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 130943988293 + 130943988294.

It is an arithmetic number, because the mean of its divisors is an integer number (130943988294).

Almost surely, 2^261887976587 is an apocalyptic number.

261887976587 is a deficient number, since it is larger than the sum of its proper divisors (1).

261887976587 is an equidigital number, since it uses as much as digits as its factorization.

261887976587 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 568995840, while the sum is 74.

The spelling of 261887976587 in words is "two hundred sixty-one billion, eight hundred eighty-seven million, nine hundred seventy-six thousand, five hundred eighty-seven".