987654226781 has 2 divisors, whose sum is σ = 987654226782. Its totient is φ = 987654226780.

The previous prime is 987654226753. The next prime is 987654226817. The reversal of 987654226781 is 187622456789.

Together with next prime (987654226817) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 728684176900 + 258970049881 = 853630^2 + 508891^2 .

It is a cyclic number.

It is not a de Polignac number, because 987654226781 - 2¹⁰ = 987654225757 is a prime.

It is a super-2 number, since 2×987654226781² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (987654226711) 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, 493827113390 + 493827113391.

It is an arithmetic number, because the mean of its divisors is an integer number (493827113391).

Almost surely, 2^987654226781 is an apocalyptic number.

It is an amenable number.

987654226781 is a deficient number, since it is larger than the sum of its proper divisors (1).

987654226781 is an equidigital number, since it uses as much as digits as its factorization.

987654226781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81285120, while the sum is 65.

The spelling of 987654226781 in words is "nine hundred eighty-seven billion, six hundred fifty-four million, two hundred twenty-six thousand, seven hundred eighty-one".