987805097561 has 2 divisors, whose sum is σ = 987805097562. Its totient is φ = 987805097560.

The previous prime is 987805097557. The next prime is 987805097581. The reversal of 987805097561 is 165790508789.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 975758718025 + 12046379536 = 987805^2 + 109756^2 .

It is a cyclic number.

It is not a de Polignac number, because 987805097561 - 2² = 987805097557 is a prime.

It is not a weakly prime, because it can be changed into another prime (987805097581) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 493902548780 + 493902548781.

It is an arithmetic number, because the mean of its divisors is an integer number (493902548781).

Almost surely, 2^987805097561 is an apocalyptic number.

It is an amenable number.

987805097561 is a deficient number, since it is larger than the sum of its proper divisors (1).

987805097561 is an equidigital number, since it uses as much as digits as its factorization.

987805097561 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 38102400, while the sum is 65.

The spelling of 987805097561 in words is "nine hundred eighty-seven billion, eight hundred five million, ninety-seven thousand, five hundred sixty-one".