489121781 has 2 divisors, whose sum is σ = 489121782. Its totient is φ = 489121780.

The previous prime is 489121757. The next prime is 489121783. The reversal of 489121781 is 187121984.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 410710756 + 78411025 = 20266^2 + 8855^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-489121781 is a prime.

It is a super-2 number, since 2×489121781² = 478480233297223922, which contains 22 as substring.

Together with 489121783, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (489121783) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 244560890 + 244560891.

It is an arithmetic number, because the mean of its divisors is an integer number (244560891).

Almost surely, 2^489121781 is an apocalyptic number.

It is an amenable number.

489121781 is a deficient number, since it is larger than the sum of its proper divisors (1).

489121781 is an equidigital number, since it uses as much as digits as its factorization.

489121781 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 32256, while the sum is 41.

The square root of 489121781 is about 22116.0977796717. The cubic root of 489121781 is about 787.9022383164.

The spelling of 489121781 in words is "four hundred eighty-nine million, one hundred twenty-one thousand, seven hundred eighty-one".